Donald Trump has promised the United States will halt “provocative” military exercises with South Korea in a major concession to Kim Jong-un after the two leaders signed a loosely-worded agreement to denuclearise North Korea.

The US President revealed on Tuesday that Washington would cease the war games, which Pyongyang regards as rehearsals for an invasion, as part of security assurances offered to Mr Kim in return for nuclear disarmament.

“We will be saving a tremendous amount of money, plus I think it is very provocative [to hold the exercises],” Mr Trump said during a lengthy press conference after talks with Mr Kim in Singapore, in the first meeting between a sitting US president and a North Korean leader.

The move, as well as Mr Trump’s description of the drills as “provocative,” represents a significant concession by Washington, which has for years insisted the exercises are defensive in nature.

Mr Trump also said he would like to see the withdrawal of the 30,000 US soldiers stationed in allied South Korea – a longstanding goal of Pyongyang – although “not right now”.

“I want to bring our soldiers back home. We have right now 32,000 soldiers in South Korea and I’d like to be able to bring them back home,” Mr Trump said. “That’s not part of the equation right now. At some point, I hope it will be. But not right now.”

A spokeswoman for US military forces in Korea said it had not received any direction to cease joint military drills.

One South Korean official told Reuters he initially thought Mr Trump had misspoken when he discussed the joint military exercises.

“I was shocked when he called the exercises ‘provocative,’ a very unlikely word to be used by a US president,” the official was quoted as saying.

Mr Trump insisted, however, that sanctions targeting the regime would remain in place until “the nukes are no longer a factor”.

Earlier on Tuesday, Mr Trump and Mr Kim signed a declaration pledging to “work towards complete denuclearisation of the Korean Peninsula” and establish “new” relations between their countries, which have no diplomatic ties.

Facing reporters, Mr Trump, who appeared without Mr Kim after the North Korean leader departed for Pyongyang, batted away suggestions North Korea was untrustworthy and that the declaration lacked specifics.

“He was very firm in the fact he wants to do this. I think he might want to do this as much or everyone more than me because they see a very bright future for North Korea,” Mr Trump said.

Mr Trump, who said he hadn’t slept in 25 hours, claimed the landmark summit had produced a breakthrough that was different from past failed agreements.

“This is not another administration that never got it started,” he said.

“And, therefore, never got it done. Chairman Kim has told me that North Korea’s already destroying a major missile engine testing site. That’s not in your signed document. We agreed to that after the agreement was signed.”

Mr Trump holds up the signed deal to the media. Photo: Getty

Despite also not being mentioned in the joint declaration, Mr Trump said he had discussed inspectors being allowed into North Korea to verify denuclearisation efforts, as well as other issues including human rights.

Many experts have criticised the agreement as lacking sufficient detail, with some arguing it was less concrete than previous deals struck in 1994 and 2005. The latest agreement does not mention any timeframe, specific actions toward denuclearisation, or any requirement for independent verification.

“We expected it would be a flop, but it’s floppier than anything we expected,” North Korean expert Andrei Lankov told NK News. “The declaration is pretty much meaningless.”

South Korea-based analyst Robert Kelly described the agreement as “depressing” and “pathetic”.

Daniel Pinkston, a former Korean linguist in the US Air Force, told The New Daily there was “nothing new really” in the agreement.

“I’ll say it’s a kimbap roll with some air in it,” he said, referring to a popular Korean rice snack, in a play on the phrase “nothing burger”.