SPY satellites have observed North Korea moving a missile into position for a possible launch, with the US saying its forces are on high alert.

Officials have told US media that spy satellites have observed DPRK mobile missile launcher movement, indicating an intermediate-ballistic missile may be being prepared.

The report comes as US Secretary of Defence James Mattis warns any further escalation could rapidly lead to war: “Yes that means for a lot of young troops they’re going to be in a wartime situation.”

Pyongyang’s state media on Tuesday reported President Kim Jong-un as “praising” his Strategic Force for drawing up a “careful” plan for a “power demonstration” to “envelop” Guam in fire.

“The nuclear force of the DPRK is strong in its guts and no one can guess its muscle as the flight trajectory of medium-to-long ballistic rocket Hwasong-12, firing data and the correct hitting-point are made public at home and abroad.”

Mr Kim said he would “watch a little more” Washington’s behaviour, but he would make an “important” decision if the US continues its “extremely dangerous reckless actions”.

“The US Imperialists caught the noose around their necks due to their reckless military confrontation racket … (but) he would watch a little more the foolish and stupid conduct of the Yankees spending a hard time of every minute of their miserable lot,” the report says.

“If the planned fire of our demonstration is carried out as the US is going more reckless, it will be the most delightful historic moment when the Hwasong artillerymen will wring the windpipes of the Yankees and point daggers at their necks.”