The meeting comes amid growing scrutiny of Pyongyang's commitment to denuclearization and as joint efforts to repatriate the remains of US troops from North Korea are taking longer than many anticipated.

"We had good meetings yesterday and ... the secretary of state will be there later this week to continue those discussions", Sanders told a White House briefing.

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 US.

Trump tweets Tuesday that "All of Asia is thrilled" that North Korea has halted missile testing and only the "Opposition Party" Democrats, including the "Fake News" is complaining.

But new satellite imagery shows an expansion of a missile-manufacturing site capable of producing missiles that could hit US military installations in Asia.

Pompeo will travel to Tokyo after Pyongyang to discuss the denuclearization of North Korea with Japanese and South Korean officials, a statement from the State Department said.

Earlier in Trump's presidency, many experts said his "maximum pressure" approach to the United States adversary actually made armed conflict significantly more likely.

President Donald Trump defended his denuclearization efforts with North Korea on Tuesday, despite the concerns of USA intelligence officials who say there is no evidence Kim Jong Un plans to give up his nuclear weapons programs.

Pompeo's visit comes days after the first in-person meeting between the USA and North Korea over the weekend.

The North Koreans were finishing construction of the plant around the same time President Trump was meeting Kim in Singapore.

Round two would come just three months after the two leaders met in Singapore and as news reports over the weekend say North Korea has continued to work on its nuclear stockpile and is trying to hide its missiles, reports the New York Post. "What I can tell you is that we're continuing to make progress", she said.

NY is looming as the next meeting place for Donald Trump and Kim Jong-un.

He said the one-year program the U.S.is proposing would cover all the North's chemical and biological weapons, nuclear programs and ballistic missiles. Thanks to an incredible new report published Friday by NBC News, it seems the hermit kingdom is increasing the production of fuel for more nuclear weapons.

Nauert similarly dodged a question on the specific timeline imposed on North Korea regarding getting rid of its illegal nuclear weapons program. Asked whether Bolton would join Pompeo for the trip to Pyongyang, she said, "Not to my awareness".

His suggestion that he single-handedly prevented a war with North Korea is impossible to test.