Two bombers operating out of Andersen Air Force Base in Guam carried out the drills, US Pacific Air Forces said in a statement.
That these plans are being developed underscores how seriously British officials see the risk of a war breaking out in Korea.
Bay's theory credits Trump with understanding China's regional goals, and North Korea's institutional confusion at living in a new world where the Americans do not back down from belligerent threats, well enough to run an effective information warfare campaign against them.
Whether Britain's Navy would be needed in the war is less clear.
A USA submarine with the capability of firing Tomahawk cruise missiles also made a port call in the South Korean city of Chinhae on Saturday, the Navy said.
The Defense Ministry after an investigation said in May that North Korea was likely behind the hacking of the Defense Integrated Data Center in September past year, but had refused to confirm media speculation that the decapitation strike plan was compromised.
Rhee Cheol-hee, a South Korean lawmaker, said the information was from his country's defence ministry. South Korea's Joint Chiefs of Staff say the bombers flew from Anderson Air Force base in Guam and entered the Korean Air Defense Identification Zone at around 8:50 p.m.
But in 2008, in the early hours of a July morning, a North Korean soldier shot dead a 53-year-old South Korean woman who had wandered across a forbidden line into a military area.
Amid escalating tensions between North Korea and the US, critics were alarmed Tuesday when a South Korean news outlet reported that President Donald Trump will travel to the demilitarized zone (DMZ) between the neighboring countries next month.
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 USA forces.
Last month, South Korea carried out a simulated attack on North Korea's nuclear test site, following joint military drills with the United States in late August.
Contrary to Clinton Administration's reconciliatory tone, the assumption of power by Bush Administration in 2000 changed the perceptions and policies of the United States towards North Korea. In this regard, responding to the recent missile tests, UN Security Council adopted strongest sanctions against North Korea - blocking the sale of coal, iron and other commodities that constitutes third of North Korea's exports. The compromised documents include wartime contingency plans drawn up by the US and South Korea.
"Although criticized by some for not resolving every issue on the Korean Peninsula, the Agreed Framework ended the immediate crisis and prevented the North from realizing its potential to develop dozens of nuclear bombs", then-Secretary of State Madeleine Albright later recalled in her memoir, Madam Secretary.