The North last month blew up its aged but only nuclear test site at Punggye-ri - where it had staged six atomic tests - in a show of goodwill before the summit.
Bolton refused to comment on intelligence matters but the United States was going into nuclear negotiations aware of Pyongyang's failure to live up to its promises in the past.
USA intelligence officials believe North Korea has been "deceiving" the US, saying the Hermit Kingdom was bolstering production for nuclear weapons at "multiple secret sites" in the past few months, a report stated. U.S. intelligence agencies became aware of the nuclear facility in 2010.
Despite Trump's rosy post-summit declaration that the North no longer poses a nuclear threat, Washington and Pyongyang have yet to negotiate the terms under which it would relinquish the weapons that it developed over decades to deter the U.S.
Washington sources last night said that Secretary of State Mike Pompeo will fly to Pyongyang on Friday for talks with Kim's top aides on the denuclearisation plan.
The facility makes solid-fuel, ballistic missiles-which would be able to strike US military installations in Asia with a nuclear weapon with little warning-as well as re-entry vehicles for warheads that Pyongyang might use on longer-range missiles able to hit the continental U.S.
North Korea intends to maintain some of its nuclear stockpile and production facilities while potentially concealing them from the United States, The Washington Post reported Saturday, citing U.S. officials.
He also urged North Korea to "continue (its) consultations with China" as it negotiates with the United States, the report said. If the leak was authorized, however, that could mean that the Trump administration is working to highlight and leverage North Korea's bad faith ahead of additional negotiations.
However, one official pointed out that, despite the assessment, the talks between the USA and North Korea were positive and Kim's decision to destroy a major missile-testing site and suspend nuclear and missile tests were a step forward.
"I finished the North Korea-U.S. summit meeting successfully, so we'd like your country to make efforts to get the sanctions lifted as soon as possible", he was quoted as saying. Trump had showered Kim with praises, calling him a "very talented man", and made security concessions in return for very little.
"I'm confident what [Trump] intended there was, 'We did reduce the threat, '" Pompeo told the panel.
Pompeo has already visited Pyongyang twice since April to meet with Kim - the first time when he was still director of the Central Intelligence Agency - and there are discussions about a possible third trip to North Korea late next week but such a visit has not yet been confirmed.