US President Donald Trump has left the country for Vietnam, where he'll hold his second summit in less than a year with North Korean leader Kim Jong-un.
Donald Trump departed Washington Monday bound for Vietnam and a second historic summit with North Korean leader Kim Jong-un, with the US president saying he will push for Korean denuclearisation.
Trump left Joint Base Andrews near Washington aboard Air Force One at 12:34 pm (1734 GMT) bound for a Wednesday-Thursday summit in Hanoi.
Shortly before his departure from the White House he spoke optimistically about what he expected would be a "very tremendous summit," adding that "we want denuclearisation" on the Korean peninsula.
The two leaders are due to meet in the Vietnamese capital, Hanoi, on Wednesday and Thursday, eight months after their historic summit in Singapore.
They had pledged to work toward the complete denuclearisation of the Korean peninsula, but their vague agreement has produced few results.
US Democratic senators and security officials have warned Trump against cutting a deal that would do little to curb North Korea's nuclear ambitions.
Trump, speaking in Washington on the eve of his departure for Vietnam, said he believed he saw eye to eye with Kim and that they had developed "a very, very good relationship".
But he appeared to play down any hope of a major breakthrough, saying he would be happy as long as North Korea maintained its pause on weapons testing.
"I'm not in a rush. I don't want to rush anybody," Trump said. "I just don't want testing. As long as there's no testing, we're happy."
North Korea conducted its last nuclear test, its sixth, in September 2017. It last tested an intercontinental ballistic missile in November 2017.
Before the freeze, the North conducted a series of tests that it says has given it powerful nuclear bombs and missiles capable of delivering them to the US mainland.
The United States has for years demanded North Korea's complete, verifiable and irreversible denuclearisation, before any concessions will be granted.
But in recent days, Trump has signalled a possible softening, saying he would love to be able to remove tough sanctions if there was meaningful progress on denuclearisation.
Speculation the Trump administration is open to a limited deal at the summit has raised expectations the two sides might declare an end to a technical state of hostilities that has existed on the Korean peninsula since the 1950-1953 Korean War ended with an armistice, not a truce.
A South Korean presidential spokesman told reporters in Seoul the two sides might agree to a formal end of the war, which the North has long called for as a major step towards normalising ties.
"The possibility is there," the spokesman, Kim Eui-kyeom told a briefing in Seoul.
In return, North Korea could allow international inspectors to observe the dismantlement of its nuclear reactor at Yongbyon, analysts say.
The US could also agree to the opening of US-North Korea liaison offices and to allow some inter-Korean projects, provided the North takes steps towards denuclearisation.
South Korea's President Moon Jae-in, who supports opening up to old rival North Korea, praised both Trump and Kim in comments in Seoul, and said those opposed to better ties on the peninsula should "discard such biased perspectives".
Trump will arrive in Vietnam on Tuesday evening, Vietnam's foreign ministry said.
He will meet Vietnam President Nguyen Phu Trong, who is also general secretary of the ruling Communist Party, on Wednesday morning.
Kim is making his way to Vietnam by train and passed through the Chinese city of Hengyang at about 3.30 pm (1830 AEDT), South Korea's Yonhap news agency reported.
That means he would be due to arrive in Vietnam early on Tuesday.
Vietnam has released few details about arrangements for the summit including its specific venue or timing.