The North Korean-Chinese border stretches 880 miles (1,415 kilometers) across China's Liaoning province, an industrial and mining heartland prone to heavy smog and painfully cold winters.
In more hospitable months, the border city of Dandong plays host to hundreds of tourists
coming to gawp at North Korea
-- from boats on the Yalu River which separates the two countries, or through binoculars on a section of the Great Wall overlooking the international boundary.
has remained largely consistent
even as relations between North Korea and its one major ally have fluctuated amid increasing nuclear and missile testing by Pyongyang and angry denunciations from Beijing.
But recent reports published on Chinese military and government websites, first highlighted by the Wall Street Journal
, show Beijing is moving to reinforce the border as tensions on the Korean Peninsula rise and some in the US call for regime change in Pyongyang.
Despite the strong ties between China and North Korea on paper -- the two countries' alliance is said to have been "forged in blood
" during the Korean War -- the border region is among China's most militarized, and Beijing has held live-fire
and helicopter attack drills
in the area in recent months.
According to a report published last month
on the official website of the People's Liberation Army (PLA), a "newly formed border defense brigade" is conducting patrols to gather intelligence, assess the situation and more accurately map out the border region -- which includes North Korea, Russia and Mongolia.
said the "whole area" has newly been placed under "24-hour video surveillance" including drones, patrol cars and high-tech cameras.
The North Korea border region is a highly strategic one for China, and has seen conflict during World War II and the Korean War, but one of Beijing's chief concerns is not military forces pouring across the border, but refugees.
"A mass movement of North Korean civilians across the border into China is a major concern, particularly given the dense population centers not far from the border, and the economic importance of Northeast China," according to a recent report
by the US-based Jamestown Foundation.
While North Korea has proved remarkably capable of shrugging off economic sanctions, the country has suffered major famines and widespread food insecurity in the past, analysts say a conflict on the peninsula would likely result in hundreds of thousands, if not millions, of civilians heading north into China, the specter of which is a "huge worry for Beijing" according to the Council on Foreign Relations.
Just as the Syrian refugee crisis has strained the resources of neighboring countries and caused widespread political strife in Europe, many in China are concerned by the hit the country's economy and security could take from even a small conflict on the Korean Peninsula.
"The stakes are huge," retired US Adm. Mike Mullen said last year
. "Instability generated on the peninsula could cascade into China, making China's challenge of providing for its own people that much more difficult."
In March, retired PLA Major General Wang Haiyun said it was "necessary to prepare military action as soon as possible for a potential war" on the peninsula.
"Once war breaks out, we should also consider setting up an international refugee camp in North Korean territory to prevent the influx of North Korean refugees," said Wang in an op-ed
in the state-owned Global Times.
Warnings of war
Tensions between Pyongyang and Washington have continued to rise amid recent claims by North Korea that it had tested a nuclear-capable intercontinental ballistic missile (ICBM)
A US defense official told CNN this week North Korea appeared to be preparing for another test
The Donald Trump administration has sought to bring pressure on China
to take action to contain its ally, but despite repeated condemnations by Beijing of North Korea's weapons testing, little progress appears to have been made.
Beijing has also criticized the US and South Korea for their rhetoric on the issue and encouraged all parties to return to the negotiating table.
However, such an invitation from Seoul to Pyongyang to resume talks went unanswered this month
The situation has led to frustration on all sides, with Trump's CIA director Mike Pompeo last week appearing to indicate support for regime change in Pyongyang
Tong Zhao, an analyst at the Carnegie Tsinghua Center for Global Policy, said that "given the growing tensions and risks of military conflicts over the peninsula, I am sure China has been enhancing its military contingency plans."
On Monday, a Chinese Ministry of Foreign Affairs (MOFA) spokesman said "military means should not be an option to solve the Korean Peninsula issue." A Defense Ministry spokesman declined to comment Monday on China's war contingency plans.
Speaking Tuesday, MOFA spokesman Lu Kang said the country's military "has maintained normal combat readiness and training status along the Chinese-North Korean border."
Earlier this year, the Chinese state-run tabloid Global Times warned "if the North Korean nuclear issue boils over, a war on the peninsula is unavoidable."
"The war will bring more risks than the tough sanctions on Pyongyang could to China," the paper said in an editorial.
"If China does not tackle the conundrum now, it will face more difficult choices in the future."