US President Donald Trump says North Korea no longer poses a nuclear threat and his top diplomat offered a hopeful timeline for a "major disarmament" despite scepticism at home that Pyongyang will abandon its nuclear weapons following this week's summit.
Trump and North Korean leader Kim Jong-un issued a joint statement after their historic meeting in Singapore on Tuesday that reaffirmed the North's commitment to "work toward complete denuclearisation of the Korean Peninsula" and gave US guarantees of security to North Korea.
Democratic critics in the US say the agreement is short on detail and the Republican president had made too many concessions to Kim, whose country is under UN sanctions for its nuclear and weapons programs and is widely condemned for human rights abuses.
Just over half of Americans say they approve of how Trump has handled North Korea, but only a quarter think the summit will lead to the denuclearisation of the Korean Peninsula, according to a Reuters/Ipsos opinion poll released on Wednesday.
North Korea's state media hailed the summit as a success, including highlighting Trump's surprise announcement after the meeting that the US would stop military exercises with South Korea, which the North has long sought.
Despite the lack of detail in the summit agreement, Trump stressed at a news conference afterward that he trusted Kim to follow through. He returned to Washington early on Wednesday and hailed the meeting, the first between a sitting US president and a North Korean leader, as a major win for American security.
"Everybody can now feel much safer than the day I took office," Trump tweeted. "There is no longer a nuclear threat from North Korea. Meeting with Kim Jong Un was an interesting and very positive experience. North Korea has great potential for the future!"
Democratic lawmakers pointed out that North Korea has often made similar statements in the past about "denuclearisation", all the while developing nuclear weapons and ballistic missiles that could be capable of striking the US.
"One trip and it's 'mission accomplished,' Mr. President? North Korea still has all its nuclear missiles, and we only got a vague promise of future denuclearisation from a regime that can't be trusted," said Adam Schiff, the top Democrat on the US House of Representatives Intelligence Committee.
"North Korea is a real and present threat. So is a dangerously naive president," he wrote on Twitter.
Senator Chris Van Hollen, also a Democrat, said of Trump's tweet about North Korea no longer presenting a threat: "This is truly delusional."
The summit statement provided no details on when Pyongyang would give up a nuclear weapons program or how the dismantling might be verified. Sceptics of how much the meeting achieved pointed to the North Korean leadership's long-held view that nuclear weapons are a bulwark against what it fears are US plans to overthrow it and unite the Korean Peninsula.
Despite Trump's assertion about the North Korean nuclear threat being over, a senior US official responsible for studying the North Korean military said the US intelligence assessment of the nuclear and other military threat posed by North Korea to US and allied forces and bases in Asia and the northwest Pacific remains unchanged.
In a post-summit announcement, Trump said on Tuesday the US would stop military exercises with South Korea while North Korea negotiated on denuclearisation.
"We save a fortune by not doing war games, as long as we are negotiating in good faith - which both sides are!" he later wrote on Twitter.
US Republican Senator Lindsey Graham called the cost reasoning "ridiculous", telling CNN, "It's not a burden on to the American taxpayer to have a forward deployed force in South Korea.
"It brings stability. It's a warning to China that you can't just take over the whole region. So I reject that analysis that it costs too much, but I do accept the proposition, let's stand down (on military exercises) and see if we can find a better way here."