Two bombers operating out of Andersen Air Force Base in Guam carried out the drills, US Pacific Air Forces said in a statement. It said the US warplanes flew with fighter jets from the South Korean air force and Japan Self-Defense Force in the first nighttime B-1 bomber exercise between the three allies.
The warplanes first conducted a simulated air-to-ground missile drill over the waters east of the Korean Peninsula and then flew over South Korea and conducted the same drill over the waters west of the peninsula, the South Korean military said.
The exercise showed the "strong ability of the alliance against the North Korean nuclear missile threat," the South Korean air force said.
The US military statement said the exercise "demonstrates how U.S. military forces in the Indo-Asia-Pacific are always ready to defend the American homeland and how the U.S. stands resolutely with Japan and the ROK to honor their unshakeable alliance commitments."
US B-1 bombers flying from Guam have been seen regularly over the Korean Peninsula amid escalating tensions with Pyongyang -- running regular training flights with Japanese and South Korean fighter jets that often provoke the ire of the North Korean regime.
North Korea has been conducting regular missile tests in recent months as well as testing a nuclear warhead in September, all part of its bid to establish a nuclear deterrent to what it sees as a military threat from the US.
China, North Korea's closest ally, has suggested that Pyongyang freeze its nuclear missile development while the US stop conducting military exercises with the South that raise fears in North Korea.
But neither side is budging in the standoff.
US President Donald Trump tweeted last week
that North Korea has been "making fools" of US negotiators for 25 years, adding that "only one thing will work" in dealing with the Kim Jong Un regime.
While US Secretary of Defense James Mattis reiterated this week that diplomacy along with international economic sanctions would remain the leading element of US strategy towards blunting North Korea, military options were being prepared.
North Korea has said Trump is "on a suicide mission" against it, with the country's foreign minister calling the US President "mentally deranged" in a speech at the United Nations last month.
Guam, from where the B-1 bombers in Tuesday drills departed, has been a particular target of North Korean threats.
After Pyongyang launched a missile test that flew over Japan in late August, the state-run Korean Central News Agency said the test was "a meaningful prelude to containing Guam," which it called the "advanced base of invasion" for US forces.
A follow-up statement from KCNA promised future launches "targeting the Pacific, where the US imperialist aggressor forces' bases are stationed."
While the attention Wednesday was on air power, upcoming US-South Korea naval exercises could further aggravate tensions.
US defense officials have told CNN that the aircraft carrier USS Ronald Reagan will conduct scheduled exercises with the South Korean navy off the peninsula at the end of this month.
While the officials said the exercises are long scheduled and not in response to recent tensions, similar exercises have prompted strong condemnation from North Korea in the past.