White House spokesman Jay Carney said on Thursday the barrage of rhetoric fitted a "regrettable but familiar" pattern of DPRK behavior.

"We're taking all the necessary precautions," Carney said, citing "prudent measures" to respond to the possible missile threat.

DPRK deploys mobile missile launchers

The Musudan has never been tested but is believed to have a range of around 3,000 km, vacuum extruder which could theoretically be pushed to 4,000 km with a light payload.

That would cover any tar-get in the ROK and Japan, and clay brick machine possibly even reach US military bases located on Guam.

The senior official told Yonhap that the mobile launchers had since been hidden in special underground facilities.

The Pentagon has said it will send missile-interceptor hollow brick machine batteries to protect its bases on Guam, a US territory some 3,380 km southeast of the DPRK and home to 6,000 US soldiers. 

Most experts think Pyongyang is not yet capable of mounting a nuclear device on a ballistic missile that could strike the US.

However, the DPRK has said it cannot assure the safety of embassies in Pyongyang after April 10, and has urged Britain, Russia and other nations to evacuate diplomatic staff. 

On Thursday, the DPRK army said it had received vacuum extruder final approval for military action,clay brick machine, possibly involving nuclear weapons, against the threat posed by US B-52 and B-2 stealth bombers participating in joint military drills with the ROK.

United Nations Secretary-General Ban Ki-moon said clay brick making machine Pyongyang must rein in its threats. ",hollow brick making machine;Nuclear threat is not a game, it is very serious," Ban said. 

"I am concerned that any misjudgment, any miscalculations ... hollow brick making machine will have very serious implications," he said.

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