Washington (CNN) North Korea's state newspaper accused the US of "hatching a criminal plot to unleash a war against the DPRK" while "having a dialogue with a smile on its face" Sunday following a report on South Korean radio that American forces in Japan were running drills aimed at invading Pyongyang.

"We can not but take a serious note of the double-dealing attitudes of the US as it is busy staging secret drills involving man-killing special units while having a dialogue with a smile on its face," the commentary from North Korea's Rodong Sinmun said, citing South Korean reports that US special units had been flown to the Philippines as part of an invasion drill.

"The US would be sadly mistaken if it thinks that it can browbeat someone through trite 'gunboat diplomacy' which it used to employ as an almighty weapon in the past and attain its sinister intention," it added.

US Forces Japan (USFJ) told CNN on Monday it was "not aware of the drills" mentioned in North and South Korean media reports.

"In general, US aircrafts and ships operate from Japan every day in support of our commitments to our allies and partners in the region and in the interests of regional peace and security," Col. John Hutcheson, the Director of public affairs of USFJ, said in a statement.

Read More