WASHINGTON • US President Donald Trump says North Korea has blown up four of its big test sites and that a process of "total denuclearisation ... has already started", but officials said there was no such evidence since a landmark summit in Singapore last week.
Mr Trump said at a Cabinet meeting in the White House on Thursday: "They've stopped the sending of missiles, including ballistic missiles. They're destroying their engine site.
"They're blowing it up. They've already blown up one of their big test sites, in fact it's actually four of their big test sites.
"And the big thing is it will be a total denuclearisation, which has already started taking place."
It was not immediately clear which North Korean test sites Mr Trump was referring to and United States officials familiar with current intelligence on North Korea's nuclear and missile test sites said there was no evidence of new moves to dismantle any sites since Mr Trump met North Korean leader Kim Jong Un on June 12.
The officials, speaking on condition of anonymity, speculated that Mr Trump might have been referring to explosions last month that North Korea said were to destroy tunnels at the Punggye-ri nuclear test site and the dismantling of a medium-range ballistic missile test stand at Iha-ri, also in May.
Mr Trump, who has been leading an international drive to press North Korea to abandon development of nuclear-armed missiles capable of reaching the US, told reporters after the June 12 summit that Mr Kim had pledged to dismantle one of his missile installations.
A US official said on Wednesday that the site Mr Trump referred to then was the Sohae Satellite Launching Ground, a major facility in the western part of the country that has been used for testing engines for long-range missiles.
US State Department spokesman Heather Nauert said US Secretary of State Mike Pompeo will be meeting the North Koreans "and talking with them at the earliest possible date" to implement what was agreed in Singapore.
She did not provide further details.
Asked on Wednesday if North Korea had done anything towards denuclearisation since the summit, US Defence Secretary Jim Mattis told reporters: "No, I'm not aware of that... obviously, it's the very front end of a process.
"The detailed negotiations have not begun. I wouldn't expect that at this point."
The US-based North Korea monitoring group 38 North said in an analysis at the end of last week there had been no sign of any activity towards dismantling of any missile test site.
In the Cabinet meeting on Thursday, Mr Trump said that "things can change."
"Personalities can change. Maybe you end up with conflict. Maybe you don't," he said.
He said both he and Mr Pompeo had established a "very strong" relationship with Mr Kim that he thought would lead to "tremendous success".
Mr Trump went on to say that the "number-one statement" in the document he and Mr Kim signed in Singapore was "we will immediately begin total denuclearisation of North Korea."
There was no such statement in the text.
In the joint statement, Mr Kim "reaffirmed his firm and unwavering commitment to complete denuclearisation of the Korean Peninsula", but made no reference to a timeline.
Going into the June 12 summit, Pyongyang repeatedly rejected unilateral nuclear disarmament.
Mr Pompeo told the same Cabinet meeting that Mr Kim had made a personal commitment, and added: "He has got his reputation on the line."