North Korea says US planning preemptive nuclear attack

File photo shows a US air force Rockwell B-1 Lancer bomber (Photos by AFP)

North Korea says the US is planning a preemptive nuclear attack after Washington announces the deployment of B-1 bombers in the Pacific.

On Saturday, the North said the US is "becoming all the more pronounced in their moves to topple down the DPRK by mobilizing all nuclear war hardware."

The strategic bombers were set to be deployed in the US Island of Guam on Saturday in a move which the Pentagon calls a routine rotation with the B-52 bombers.

"The enemies are bluffing that they can mount a preemptive nuclear strike on the DPRK by letting fly B-1B over the Korean peninsula within two-three hours in contingency," said a statement released on North Korean state media.

On July 29, the US air force announced that it would be the first time that B-1s are sent to Guam since April 2006.

Designed by Rockwell International (now part of Boeing), the Rockwell B-1 Lancer is a four-engine heavy strategic bomber used by the US air force as a supersonic bomber with Mach 2 speed.

This undated photo released by North Korea's official Korean Central News Agency (KCNA) on July 21, 2016 shows a missile fired during a drill by Hwasong artillery units of the Strategic Force of the Korean People's Army.

"Such moves for bolstering nuclear force exposes again that the US imperialists are making a preemptive nuclear strike on the DPRK a fait accompli," added the Pyongyang statement.

Earlier in July, the North pledged a “physical response” to US deployment of the sophisticated THAAD missile system in Korean Peninsula. 

THAAD interceptor is launched during a test in this undated handout photo provided by the Pentagon.

Tensions have been flaring in the region since January, when North Korea said it had successfully detonated a hydrogen bomb, its fourth nuclear test, and vowed to build up its nuclear program as deterrence against potential aggression from the US and its regional allies.    

A month later, Pyongyang launched a long-range rocket which it said placed an earth observation satellite into orbit. However, Washington and Seoul denounced it as a cover for an intercontinental ballistic missile test.​