A pair of American B-52H bombers was escorted by two Japanese F-2 fighter aircraft and two South Korean KF-16 fighter jets during a trilateral flight on Friday.

North Korea, on Sunday, blasted recent combined air drills conducted by South Korea, the US and Japan, saying such joint military actions are "the main danger factors heightening the level of

Russia has warned the US, South Korea and Japan against forming an alliance targetting North Korea amid rising military cooperation between Russia and Pyongyang.