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.

Vice President Mike Pence told American ambassadors on Wednesday that North Korea has failed to take any substantive steps to give up its nuclear weapons, even as President Trump is moving toward a second meeting with Kim Jong-un, the North Korean leader.

“While the president has started a promising dialogue with Chairman Kim,” Mr. Pence told the gathering at the State Department, “we still await concrete steps by North Korea to dismantle the nuclear weapons that threaten our people and our allies in the region.”

With the unequivocal statement, Mr. Pence seemed to directly contradict the president’s claim on Twitter, after his first summit meeting in June, that “there is no longer a Nuclear Threat from North Korea.” At the time, many of Mr. Trump’s top aides cringed at the declaration, fearing it would take the economic pressure off the North to disarm.

The fear seems well founded: China and Russia have resumed many economic enterprises with North Korea.