NORTH KOREA threatened retaliation today after the United States flew long-range bombers over South Korea during joint war games with South Korean warplanes.

The US flew B-1B bombers to train with other US and South Korean fighter jets on Tuesday. South Korea’s Defence Ministry had said the drill was meant to show the two countries’ combined deterrence capability against North Korea’s nuclear programme.

The US and South Korea routinely hold joint military exercises that they describe as defensive. But North Korea regards them as provocative and an invasion rehearsal.

“The recent military move of the US and the Republic of Korea is an open threat to the security of our state and a grave provocation that raises the military tension in the region to an extremely dangerous level,” an unidentified spokesperson for North Korea’s Defence Ministry said in a statement carried in state media.

North Korea warned it “will deter by dint of powerful force the US aggressive attempt to permanently fix the malignant instability element in the security environment of the region.”

South Korea’s air force announced later toay that it was beginning a huge two-week “Freedom Flag” aerial exercise with US forces.