- US bomber flyover was a response to North Korea's nuclear test
- North Korea says US using flyovers in plan to launch pre-emptive attack
"They are bluffing that B-1Bs are enough for fighting an all-out nuclear war," said a statement from Pyongyang's Korean Central News Agency.
Two of the powerful US bombers, joined by US and South Korean fighter jets, flew over Osan Air Base south of Seoul on Tuesday to show US anger with North Korea's nuclear weapons test four days earlier.
Pyongyang claimed Friday's test showed it had a nuclear warhead that could be mounted on ballistic missiles, a possibility that increases fears for US allies in the region and also poses a threat to US bases in South Korea, Japan and Guam.
The US commander in South Korea, Gen. Vincent K. Brooks, called the North's nuclear test "a dangerous escalation" and "an unacceptable threat."
A US intelligence official said North Korea is the only country in the world that threatens others with a nuclear attack, and that Pyongyang shows no signs of backing off its nuclear program.
North Korea countered Wednesday that it was the US that was inflaming tensions.
"The US imperialists keep letting their nuclear strategic bombers fly over South Korea in a bid to seek an opportunity of mounting a preemptive nuclear attack," the KCNA statement said.
North Korea's military was prepared to stop any US moves, it said, with a closing warning to Washington.
"They had better stop their rash actions," the statement said.