US president also says it was possible he and North Korean leader could sign a deal to end the 1950-53 Korean War.

US President Donald Trump has said he is open to inviting North Korean leader Kim Jong-un to the White House if he deemed next week’s summit a success, while also signalling he was willing to walk away if he thought talks did not go well.

“Certainly if it goes well. I think it would be well received,” Trump said on Thursday during a joint press conference with Japanese Prime Minister Shinzo Abe.

“I think he would look at it very favourably so I think that could happen.”

On Thursday, Trump repeated what he said last week that it was possible he and Kim could sign an agreement to end the 1950-53 Korean War, which was concluded only with a truce, not a peace treaty.

“We could sign an agreement, as you know that would be a first step … We’re looking at it, we’re talking about it with a lot of other people,” Trump told reporters. “That’s probably the easy part. The hard part remains after that.”

Trump added that he hoped someday US relations with Kim’s secretive Pyongyang government could be normalised.

The main issue for the June 12 summit in Singapore is the US demand for North Korea to abandon a nuclear weapons programme that now threatens the United States.

North Korea has rejected giving up its arsenal unilaterally, and defends its nuclear and missile programmes as a deterrent against what it sees as US aggression.

The US stations 28,500 troops in South Korea, a legacy of the Korean War.

‘Complete, verifiable denuclearisation’

US Secretary of State Mike Pompeo on Thursday reemphasised Washington’s stance going into the talks.

Pompeo said Trump will reject anything short of “complete, verifiable and irreversible denuclearisation of the Korean Peninsula.

“President Trump is hopeful. But he’s also going into the summit with his eyes wide open,” Pompeo said at a White House briefing after the Trump-Abe news conference.

Pompeo, however, added that the US would work to guarantee North Korea’s security should it denuclearise.

Trump “is prepared to ensure a DPRK free of its weapons of mass destruction is also a secure North Korea,” Pompeo said.

Pompeo plans to stay in the region following the summit to meet officials from Japan and South Korea and to travel to China, an important North Korean ally, to discuss the next steps involving Pyongyang.

‘Bold steps’

Trump told reporters on Thursday he would quit the talks if he felt he must, and would ramp up US sanctions pressure on North Korea if the talks did not go well.

“I am totally prepared to walk away,” he said.

Meanwhile, Pompeo, who has twice met Kim in Pyongyang, said he believes the North Korean leader is prepared to take “bold” steps to alter the course of his nation.

“He has indicated to me personally that he is prepared to denuclearise,” Pompeo said.

“That he understands that the current model doesn’t work, that he’s prepared to denuclearise and that two, he understands that we can’t do it the way we’ve done it before. That it has to be big and bold and we have to agree to making major changes.”

Asked whether the two sides had narrowed their differences on how they defined denuclearisation, Pompeo said they had, but he declined to give details.