White House officials are reportedly looking to schedule a second meeting between Kim Jong Un and Donald Trump in New York City this September, in an attempt to progress from the two leaders' first summit in Singapore.
Some US officials believe that North Korea has about 65 nuclear warheads.
"This is why people want North Korea to declare all its facilities up front", Wit said.
Bruce Klingner is with the Heritage Foundation, a research group in Washington, D.C. He said satellite images show that North Korea has expanded a nuclear center and a missile production center.
"There is absolutely unequivocal evidence that they are trying to deceive the USA", the official said.More news: Wimbledon: Nadal and Del Potro react to Federer losing Grand Slam record
In testimony before a US Senate committee, Mr Pompeo declined to go into specifics but suggested the scope of what the US has in mind.
Kim made his third trip to China this year just a week after he met U.S. President Donald Trump at the historic summit in Singapore. "He's a great negotiator", he said. North Korea declared on New Year's Day that it no longer needed those tests because it had perfected its nuclear weapons program.
Wayne Lee, Steve Herman reported this story for VOA News. The officials insisted on anonymity to discuss sensitive assessments about a country that has always been one of the most hard targets for spy agencies to penetrate.
A USA official told The Associated Press that the Post's report was accurate and that the assessment reflected the consistent view across US government agencies for the past several weeks.
Asked about Trump's claim that the North Korea threat had been eliminated, Pompeo said Trump had meant to say only that the threat had been reduced. Pyongyang has often had its own complaints about Washington over slow delivery of aid and imposition of sanctions.More news: Varane compares France’s Mbappe to Brazil icon Ronaldo
The report came amid increasing skepticism voiced by USA intelligence officials about Kim's pledge to denuclearize his country and mounting evidence the rogue regime was continuing to develop its missile and nuclear sites. Either Kim Jong-un deceived President Trump or Kim does not control the military in North Korea.
Bolton told CBS's Face the Nation that Washington has devised a programme to dismantle North Korea's weapons of mass destruction and ballistic missile programs in a year.
While Kim may seek to turn his finished weapons into security and economic benefits, in any agreement he will also attempt to retain enough of his manufacturing and research capabilities to allow for a quick resumption of his nuclear weapons program in case diplomacy falls apart, said Hwang Ildo, a professor at Seoul's Korea National Diplomatic Academy.
The US and North Korea have expressed different expectations for the pace and sequence of North Korea's disarmament and relief from global sanctions.
FILE - In this June 27, 2018, file photo, U.S. National security adviser John Bolton listens to question as speaks to the media after his talks with Russian President Vladimir Putin in Moscow, Russia.More news: Marcelo trains with Brazil ahead of Mexico last-16 clash
John Bolton, Trump's national security advisor, said on Sunday that the United States plans for North Korea to dismantle its chemical, biological, nuclear, and ballistic missile programs in a year's time.