The Thunder military exercise began on Friday and is scheduled to continue for two weeks.
It will include around 100 aircraft, including F-15Ks, F-16s, and F-22 radar-evading fighter jets.
The military drill is being carried out by the US 7th Air Force and South Korea’s Air Force Operations Command.
A source said: “In the training, the U.S. F-22 stealth fighters have already participated, while the B-52 has yet to join.
“It appears that the B-52 may not attend the exercise, which runs through May 25.”
The announcement was made shortly after a phone call between North and South Korea about the cancelled summit.
North Korea has repeatedly expressed its concern over the deployment of B-52 bombers over the Korean peninsula.
The country’s Korean Central News Agency stated the drills were a rehearsal for invasion, and deemed them a provocation.
The insular nation suspended talks with South Korea which were due to take place on Wednesday due to the joint military drill, and has threatened to cancel the planned summit between Kim Jong-un and Donald Trump on June 12 in Singapore.
Commenting on the situation, White House Press Secretary Sarah Sanders said: “We are aware of the South Korean media report.
“The United States will look at what North Korea has said independently, and continue to coordinate closely with our allies.”
South Korea’s Defence Minister Song Young-moo is now set to hold an emergency meeting with General Vincent Brooks, Commander of US Forces in Korea, to discuss the unexpected move from the hermit kingdom.
There are fears that North Korea’s protest could jeopardise ongoing peace negotiations established following the landmark inter-Korea summit between Kim Jong-un and South Korea President Moon Jae-in in April.
The West is also concerned the North may use the inter-Korean declaration to oppose South Korea and the US’s joint military drills, which form a central part of the their defence procedures.
Anthony Ruffiero, a senior fellow at the Foundation for Defence of Democracies, said: “North Korea’s actions today are not surprising.
“They come straight from the Kim Jong-il playbook on negotiations: Raise expectations of a diplomatic breakthrough, cancel or suggest Pyongyang might cancel the meeting and then push for more concessions to have the meeting.”
More to follow…