In an undated photo released on November 28, North Korea leader Kim Jong Un is seen on a field trip to see the airwomen of the KPA Air and Anti-Air Force. North Korean Newspaper Rodong Sinmun reported Kim "guided a flight drill of pursuit airwomen of the KPA Air and Anti-Air Force. He went out to an airport's runway to learn about the plan for solo take-off and landing drill by women pilots of pursuit planes and guide their flight."
A picture released by the North Korean Central News Agency shows Kim appearing without his cane at an event with military commanders in Pyongyang on Tuesday, November 4. Kim, who recently disappeared from public view for about six weeks, had a cyst removed from his right ankle, a lawmaker told CNN.
Kim is seen walking with a cane in this image released Thursday, October 30, by the state-run Korean Central News Agency.
Kim talks with officials during an airmen inspection.
Kim sits in the pilot's seat of a fighter jet during the inspection.
Kim sits at a desk during the inspection.
This undated photo, released Tuesday, October 14, by the KCNA, shows Kim inspecting a housing complex in Pyongyang, North Korea. International speculation about Kim went into overdrive after he failed to attend events on Friday, October 10, the 65th anniversary of the Workers' Party. He hadn't been seen in public since he reportedly attended a concert with his wife on September 3.
A picture released by the KCNA shows Kim and his wife watching a performance by the Moranbong Band on Wednesday, September 3, in Pyongyang.
Kim tours a front-line military unit in this image released Wednesday, July 16, by the KCNA.
Kim poses for a photo as he oversees a tactical rocket-firing drill in June.
Kim watches a tactical rocket-firing drill in June.
A North Korean soldier patrols the bank of the Yalu River, which separates the North Korean town of Sinuiju from the Chinese border town of Dandong, on Saturday, April 26.
A soldier looks through binoculars inside a sentry post along the bank of the Yalu River on Monday, April 7.
In this photo released Thursday, April 24, by the Korean Central News Agency, Kim smiles with female soldiers after inspecting a rocket-launching drill at an undisclosed location.
A picture released Tuesday, March 18, by the KCNA shows Kim attending a shooting practice at a military academy in Pyongyang.
A North Korean soldier uses binoculars on Thursday, February 6, to look at South Korea from the border village of Panmunjom, which has separated the two Koreas since the Korean War.
A North Korean soldier kicks a pole along the banks of the Yalu River on Tuesday, February 4.
A photo released by the KCNA on Thursday, January 23, shows the North Korean leader inspecting an army unit during a winter drill.
Kim inspects the command of an army unit in this undated photo released Sunday, January 12, by the KCNA.
Kim visits an army unit in this undated photo.
A picture released by the KCNA on Wednesday, December 25, shows Kim visiting an army unit near the western port city of Nampo.
Kim inspects a military factory in this undated picture released by the KCNA in May 2013.
Kim visits the Ministry of People's Security in 2013 as part of the country's May Day celebrations.
A North Korean soldier, near Sinuiju, gestures to stop photographers from taking photos in April 2013.
North Korean soldiers gather by the docks in Sinuiju, near the Chinese border, in April 2013.
North Korean soldiers patrol near the Yalu River in April 2013.
Kim is briefed by his generals in this undated photo. On the wall is a map titled "Plan for the strategic forces to target mainland U.S."
Kim works during a briefing in this undated photo.
In this KCNA photo, Kim inspects naval drills at an undisclosed location on North Korea's east coast in March 2013.
Kim, with North Korean soldiers, makes his way to an observation post in March 2013.
Kim uses a pair of binoculars to look south from the Jangjae Islet Defense Detachment, near South Korea's Taeyonphyong Island, in March 2013.
Kim is greeted by a soldier's family as he inspects the Jangjae Islet Defense Detachment in March 2013.
Kim is surrounded by soldiers during a visit to the Mu Islet Hero Defense Detachment, also near Taeyonphyong Island, in March 2013.
Kim arrives at Jangjae Islet by boat to meet with soldiers of the Jangjae Islet Defense Detachment in March 2013.
Soldiers in the North Korean army train at an undisclosed location in March 2013.
In a photo released by the official North Korean news agency in December 2012, Kim celebrates a rocket's launch with staff from the satellite control center in Pyongyang.
Kim, center, poses in this undated picture released by North Korea's official news agency in November 2012.
Kim visits the Rungna People's Pleasure Ground, under construction in Pyongyang, in a photo released in July 2012 by the KCNA.
A crowd watches as statues of North Korean founder Kim Il Sung and his son Kim Jong Il are unveiled during a ceremony in Pyongyang in April 2012.
A North Korean soldier stands guard in front of an UNHA III rocket at the Tangachai-ri Space Center in April 2012.
In April 2012, Pyongyang launched a long-range rocket that broke apart and fell into the sea. Here, the UNHA III rocket is pictured on its launch pad in Tang Chung Ri, North Korea.
A closer look at the UNHA III rocket on its launch pad in Tang Chung Ri, North Korea.
A military vehicle participates in a parade in Pyongyang in April 2012.
North Koreans wave flags in front of portraits of Kim Il Sung, left, and Kim Jong Il during celebrations to mark the 100th birth anniversary of Kim Il Sung in Pyongyang in April 2012.
North Korean soldiers relax at the end of an official ceremony attended by leader Kim Jong Un at a stadium in Pyongyang in April 2012.
Kim Jong Un applauds as he watches a military parade in Pyongyang in April 2012.
A North Korean soldier stands on a balcony in Pyongyang in April 2012.
North Korean soldiers march during a military parade in Pyongyang in April 2012.
Soldiers board a bus outside a theater in Pyongyang in April 2012.
North Korean performers sit below a screen showing images of leader Kim Jong Un in Pyongyang in April 2012.
North Korean soldiers salute during a military parade in Pyongyang in April 2012.
North Korean soldiers listen to a speech during an official ceremony attended by leader Kim Jong Un at a stadium in Pyongyang in April 2012.
Members of a North Korean military band gather following an official ceremony at the Kim Il Sung stadium in Pyongyang in April 2012.
North Korean military personnel watch a performance in Pyongyang in April 2012.
A North Korean controller is seen along the railway line between the Pyongyang and North Pyongan provinces in April 2012.
A North Korean military honor guard stands at attention at Pyongyang's airport in May 2001.
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
Kim Jong Un and North Korea's military
STORY HIGHLIGHTS
- NEW: U.S. Ambassador Rice: The sanctions will "bite hard"
- NEW: China is "firmly committed" to peace on the Korean peninsula, ambassador to U.N. says
- NEW: The resolution will clamp down on North Korea's officials, banks and cargo
- Analysts say China is a key to determining whether the sanctions deter North Korea
(CNN) -- The U.N. Security Council unanimously passed tougher sanctions against North Korea Thursday targeting the secretive nation's nuclear program hours after Pyongyang threatened a possible "preemptive nuclear attack."
"These sanctions will bite, and bite hard," U.S. Ambassador to the United Nations Susan Rice said after the vote.
China, North Korea's key ally, could have used its veto power to block the sanctions. Instead, after weeks of negotiating, it signed on to the final draft.
"China is a country of principle," China's U.N. Ambassador Li Baodong said. "We are firmly committed to safeguarding peace and stability on the Korean peninsula."
U.N. toughens sanctions on North Korea
China's role in North Korean sanctions
North Korea threatens nuclear strike
Leading up to the vote, Pyongyang ratcheted up its bellicose rhetoric.
A spokesman for the North Korean foreign ministry suggested the United States "is set to light a fuse for a nuclear war."
As a result, North Korea "will exercise the right to a preemptive nuclear attack to destroy the strongholds of the aggressors and to defend the supreme interests of the country," the country said in a statement carried by the state-run Korean Central News Agency.
Despite the strong language, analysts say North Korea is years away from having the technology necessary to mount a nuclear warhead on a missile and aim it accurately at a target. And, analysts say, North Korea is unlikely to seek a direct military conflict with the United States, preferring instead to try to gain traction through threats and the buildup of its military deterrent.
But the threat came amid increased concern over Pyongyang's dogged efforts to advance its nuclear and missile technology after a recent long-range rocket launch and underground atomic blast.
On Tuesday, North Korea said it planned to scrap the armistice that stopped the Korean War in 1953 and warned it could carry out strikes against the United States and South Korea.
Analysts: 'Boxed in' North Korea's bluster 'particularly dangerous'
The rhetoric came not only in advance of the U.N. vote, but also as military drills take place on either side of the heavily armed border that divides the two Koreas.
This week, the United States and South Korean began two months of joint exercises, known as Foal Eagle. North Korea has called the annual training exercises "an open declaration of a war," but South Korea says it notified Pyongyang that the drills "are defensive in nature."
Anger from North Korea over sanctions
North Korea at it again with threats
North Korea's nuclear ambitions
North Korea's nuclear threat Thursday "may suggest that Pyongyang feels even more boxed in than usual," said Michael Mazza of the American Enterprise Institute.
And while a nuclear attack itself is not an immediate palpable threat, "This surge in provocative rhetoric is particularly dangerous," added Michael Auslin, also with the institute. "South Korea's new president (Park Geun Hye) can't be seen to back down in the face of the North's threats, while (new North Korean leader) Kim Jong Un may feel that his successful missile and nuclear tests give him the ability to keep pressuring Seoul. The two may wind up talking themselves into conflict."
South Korea's U.N. Ambassador Kim Sook said Thursday the new resolution "reflects the will of the international community," which "will never tolerate North Korea's repeated violations and North Korea's nuclear and ballistic missile program."
"Each violation will be met by stronger responses and measures," he added.
Will the new sanctions work?
The goal of the new sanctions is to stymie the activities of North Korean banks and cash couriers who might be funneling money to the secretive regime's nuclear and missile programs.
It will be tougher for the regime to move large sums of cash stuffed into suitcases, Rice said.
The U.N. resolution also outlines measures to step up scrutiny of suspicious sea shipments and air cargo. And it expands restrictions to encompass several institutions and senior officials in the North's weapons industry, as well as a range of materials and technology known to be used in uranium enrichment.
It also blocks the sale of luxury goods -- such as yachts and certain high-end jewelry -- to North Korea.
"As a result, North Korea's ruling elite, who have been living large while impoverishing their people, will pay a price" for the ongoing nuclear activities, Rice said.
Some doubt whether the new measures will make much difference.
Sanctions imposed after previous nuclear tests and rocket launches have failed to deter Pyongyang.
China will go a long way toward determining whether the new sanctions really do have "bite," analysts say.
"As long as China allows North Korea to operate, as long as China provides food, energy assistance, and investment, the sanctions really don't matter," said Doug Bandow of the Cato Institute.
North Korea notoriously allows many of its people to live in malnutrition and starvation. Still, the country needs a functioning economy, partly to finance its military, Bandow explained.
"Kim Jong Un is now paying the price for going ahead with a nuclear test despite Chinese warnings not to create trouble during the political transition that has been under way in Beijing the past year," Mark Fitzpatrick, director of the Non-Proliferation and Disarmament Programme at the UK-based International Institute for Strategic Studies, said this week.
Future levels of Chinese grain sales to North Korea are a possible indicator of Beijing's commitment to putting meaningful pressure on Pyongyang, he said.
Ken Gause, an analyst with CNA, said the new sanctions won't deter North Korea from building up its nuclear program.
"North Korea last year inserted language into its constitution that the country is a nuclear power. To walk back from this, especially under pressure from the outside world, would undermine Kim Jong Un's legitimacy and make him vulnerable. He will not do this," said Gause.
North Korea casts U.N. sanctions as part of an aggressive, U.S.-led conspiracy against it.
READ: Report: North Korea threatens to end armistice
READ: Five things to know about North Korea's planned nuclear test
READ: Tough U.N. action vowed after North Korean nuclear test
Simmering tensions
North Korea said the underground nuclear blast it conducted February 12 was more powerful than its two previous detonations and used a smaller, lighter device, suggesting advances in its weapons program.
It was the first nuclear test the isolated state has carried out since Kim inherited power in December 2011 after the death of his father, Kim Jong Il, who made building up North Korea's military strength the focus of his 17-year rule.
The test followed the North's long-range rocket launch in December that succeeded in putting an object in orbit. Pyongyang insisted the launch had peaceful aims, but it was widely viewed as a test of its ballistic missile technology.
Long history
North and South Korea have technically been at war for decades. The 1950-53 civil war ended in a truce rather than a peace treaty.
China supported the North with materiel and troops in the Korean War. The United States backed the South in the conflict, with soldiers from the two countries fighting side by side. About 28,500 U.S. soldiers are currently stationed in South Korea.
CNN's Elise Labott, Richard Roth, and Joe Sterling contributed to this report.