The Journal report comes as Secretary of State Mike Pompeo visits Pyongyang on Friday, where he is likely to push North Korea for more solid commitments regarding denuclearization. Pompeo joked once the meeting started that if he comes again after this, his third trip to North Korea this year, he will have to start paying taxes.
Late last month, 38 North, a US -based North Korea watchdog, reported the North was making improvements at one of the country's nuclear research centres at a "rapid pace" despite Kim's pledge to denuclearize the Korean peninsula. Trump asked if he knew the song, and Kim replied that he didn't.
The United States is seeking North Korea denuclearization, but the State Department says it is now on the quest for "final, fully verified denuclearization" and not the complete, verifiable, irreversible denuclearization of North Korea.
Secretary of State Mike Pompeo is in Pyongyang to discuss the next steps toward denuclearization following the summit in Singapore. Geneva was considered a major candidate city for the first-ever North Korea-U.S. summit, which took place in Singapore on June 12.
"Nothing could be further from the truth".
Some officials in the State and Defense Departments and in USA intelligence agencies are anxious that Trump has put himself at a disadvantage by overstating the results of the Singapore summit. "Our policy toward North Korea has not changed, we're committed to a denuclearized North Korea".
But the US ability to verify the accuracy of any North Korean list is limited due to the lack of a "high confidence" accounting of the North's nuclear arsenal, such as the number of warheads and uranium enrichment facilities, especially if they are not operational, they said.
During that conversation, Kim brought up the fact that Trump repeatedly called him "little rocket man" over the past year, but did not get the reference.
Since meeting Kim in Singapore last month, Mr Trump has been bullish about hopes for peace, boasting that the threat of nuclear war is over.
As it happens, Elton John also came up at Trump's campaign rally in Montana Thursday night.
Analysts also note that nuclear weapons systems can be improved and expanded without full-blown tests; for example, South Korean intelligence reportedly believes North Korea is quietly working on submarines that can launch nuclear-armed ballistic missiles.
"Eight months, no nuclear testing, no missiles, no anything", he added, saying that lack of testing by North Korea was a sign of success.
The sub under construction at Sinpo may be a successor to that Gorae-class boat, advancing a program that USA officials consider a threat because it could allow North Korea to achieve greater surprise for a nuclear strike.