This information comes to light as the North Korean threat continues to grow alongside President Donald Trump's perceived threats of military action.
Tensions have soared between the United States and North Korea following a series of weapons tests by Pyongyang and a string of increasingly bellicose exchanges between Trump and North Korean leader Kim Jong Un.
The last flight by U.S. bombers was 17 days earlier when four US F-35B stealth fighter jets and two B-1Bs flew over the peninsula. In August, Pyongyang threatened to fire intermediate-range missiles towards the vicinity of Guam, a U.S. Pacific territory that is frequently subjected to sabre-rattling from the North.
South Korean defence authorities on yesterday said the bombers staged a simulated air-to-ground missile firing drill with two South Korean fighters over the Sea of Japan (East Sea).
The compromised documents include wartime contingency plans drawn up by the US and South Korea and also include reports to the allies' senior commanders, Rhee Cheol-hee, a South Korean lawmaker was quoted as saying BBC Tuesday.
Trump hosted a discussion on Tuesday on options to respond to any North Korean aggression or, if necessary, to prevent Pyongyang from threatening the United States and its allies with nuclear weapons, the White House said in a statement.
On Monday he tweeted: "Our country has been unsuccessfully dealing with North Korea for 25 years, giving billions of dollars and getting nothing".
South Korean warships including the nation's first Aegis destroyer, Sejongdaewang (L), in this file photo.
Bishop said Australia supports what she called "the tough sets of comprehensive sanctions" against North Korea, saying the North "will be deterred from carrying out any further illegal test" and "will be compelled to return to the negotiating table".
Speaking in Beijing, Chinese Foreign Ministry spokeswoman Hua Chunying reiterated a call for all parties involved with the standoff in North Korea to exercise restraint, describing the situation as extremely complex and serious.
To make the complex fully operational again, North Korea would also be hard pressed to replace the electricity supply that came from South Korea, according to the Kaesong business owners.