Satellite photographs taken in the last month indicate that the regime may be working on one or two liquid fuel intercontinental ballistic missiles (ICBMs), officials told The Washington Post.
Trump traveled to Singapore in June for a summit with Kim and, following the meeting, Trump announced that North Korea no longer posed a nuclear threat - despite a lack of evidence proving that the North Koreans would cease to continue its nuclear program.
White House counselor Kellyanne Conway on Tuesday played down the significance of the Post report.
He declined to say whether Pyongyang is constructing new missiles. "Things don't change overnight", Conway later added.
Major-General Kim Do Gyun, the South's chief negotiator in charge of North Korea policy at the Defence Ministry, told reporters he would make efforts to craft "substantive" measures to ease tensions and build trust.
The North demonstrated sharp progress in its program previous year when it test-fired numerous missiles and conducted its sixth and most powerful nuclear test.
A senior State Department official said Tuesday that Pompeo will urge Asian countries at a meeting in Singapore this weekend to enforce United Nations sanctions on North Korea.
Trump threatens Turkey sanctions over pastor
This declaration came a day after a Turkish court allowed Brunson to leave prison for house arrest to help him recover his health. The pastor's transition to house arrest led many government officials, including President Donald Trump, to speak on the matter.
In late June, it was reported that U.S. intelligence agencies believe North Korea had upped uranium production in recent months and that North Korean officials were seeking to deceive the United States in order to extract more concessions in talks.
The remains of 55 soldiers returned by North Korea last week are likely Americans, a USA official said Wednesday.
From there, the remains will be taken to a laboratory in Hawaii for possible identification, with the goal of matching them with any of the 7,697 US personnel who remain are unaccounted for after the Korean War.
Some 5,300 of those are believed to have been lost in North Korea, which is separated from the South by one of the world's most fortified borders. "North Korea has great potential for the future!"
In Singapore, Donald Trump met alone with dictator Kim Jung Un before signing a document that had no dates, no details, no guidelines for ending the buildup of nuclear weapons in North Korea. The Diplomat earlier this month had exclusively revealed North Korea's covert uranium enrichment site of Kangson, also on the outskirts of Pyongyang.
Most died on the battlefield and were buried in shallow graves or in cemeteries that were meant to be temporary, but some also perished in POW camps run by North Korea or China, experts say. But there is a broad consensus among USA intelligence agencies that Kangson is one of at least two secret enrichment plants. The soldier's family had been notified, though it was not clear if his remains were among those found, Byrd said. "But even if they are, you still have a nuclear deterrent, so it would still be a huge risk for the U.S.to try to attack". It has in the past two years quickly advanced its nuclear programme.
Foreign-policy experts have remained skeptical about North Korea's intentions, given its history on withdrawing from prior agreements.