US heavy bombers and stealth jet fighters delivered a show of force directed at North Korea in a live-fire drill on Thursday, two days after Pyongyang’s provocative test-launch of a ballistic missile that flew over northern Japan.

Two B-1B "Lancer" bombers from Guam and four F-35B stealth jet fighters from the Marine Corps’ Iwakuni airbase in Japan joined four South Korean jet fighters and two from Japan in the exercise over Japanese and South Korean air space, US military officials said.

US and South Korean aircraft dropped live munitions onto the Pilseung shooting range in Gangwon province, some 150 kilometres (94 miles) south of the Demilitarized Zone dividing the two Koreas.