Trump and Kim have made history shaking hands at the start of their summit in Singapore. It's the first time a US president has met with a North Korean leader.
Donald Trump and Kim Jong-un shared warm words and a historic handshake Tuesday as they held an unprecedented summit to tackle a tense decades-old nuclear stand-off and an enmity stretching back to the Cold War.
The two men clasped hands beneath the white-washed walls of an upscale hotel in neutral Singapore, before sitting down for a half-day of meetings with major ramifications for the region and the world.
It is the first-ever meeting between sitting leaders of the two nuclear-armed foes and was unthinkable just months ago, when fears of war mounted amid missile tests and verbal insults.
The pair shook hands for several seconds, Trump reaching out to touch the North Korean leader on his right shoulder.
As they sat down for their one-on-one meeting, the US leader -- who had said he would know "within the first minute" if he a deal would be possible with his North Korean counterpart -- predicted a "terrific relationship" with Kim.
For his part, the North's leader made a reference to the two countries' history of war and acrimony, but noted the fact of their meeting showed they could overcome the past.
"The way to come to here was not easy," Kim said as he sat with Trump. "The old prejudices and practices worked as obstacles on our way forward but we overcame all of them and we are here today."
Trump responded: "That's true."
The imagery for the high-stakes meeting was undoubtedly positive and Kim Yong-hyun, professor at Dongguk University in Seoul said: "The atmosphere of the summit looks very good."
"It will be hard for this meeting to agree on specific deals but it carries considerable significance as a starting point," he said.
'Fire and fury'
The warm words seemed an age ago from when Trump was threatening to rain down "fire and fury" on Pyongyang and Kim attacked Trump as a "mentally deranged US dotard", as he fired off a series of provocative weapons tests.
Trump had cajoled the international community to exert "maximum pressure" to buckle Kim's regime if he did not give up his nuclear weapons.
The Singapore summit is a potentially legacy-defining meeting for both men -- comparable to president Richard Nixon's 1972 visit to China, or Ronald Reagan's summit 1986 with Mikhail Gorbachev in Reykjavik.
And it is part of what Trump calls a "one-time" offer to resolve the stand-off through diplomacy.
"We will all know soon whether or not a real deal, unlike those of the past, can happen!" Trump tweeted shortly before departing for the summit.
But many agreements have been made in the past with North Korea that have later fallen apart.
On the table is the vexed question of denuclearisation -- a euphemism that means vastly different things to the two parties.
It remains far from clear that Pyongyang is willing to give up its nukes -— weapons that the regime sees as its ultimate guarantee of survival.
And on the eve of the meeting, aides for both men were still scrambling to narrow yawning differences.
Secretary of State Mike Pompeo said Monday that the United States was willing to offer Pyongyang "unique" security guarantees if it denuclearises.
The pair -- Kim in his thirties and consolidating his dictatorship, Trump in his seventies and struggling to bend Washington to his impetuous will -- are unlikely protagonists, both instantly recognisable, so much larger-than-life as to be cartoonish.
But their work Tuesday was deadly serious.
They represent nations that are still technically at war, even if the mortars, carbines and gunships of the bloody 1950s conflict have long since fallen silent.
The totalitarian regime has made rapid progress towards marrying nuclear and missile technology that would put Los Angeles, New York and Washington within striking distance of a nuclear holocaust.
The United States says that is unacceptable and will be dealt with, one way or another.
For North Korea the talks are hugely significant.
Standing beside the US president in front of a phalanx of cameras is an enormous step towards ending decades of international isolation and critics say it legitimises one of the world's most ruthless regimes.
Trump will use what he says are legendary instincts to see whether Kim if bluffing, buying time or is serious.
Kim and Trump met first in a closed session lasting around 40 minutes, before a larger meeting with key advisers.
But the summit itself is unlikely to be the end game -- more likely it is the start of a longer process of negotiation.
The discussions "will set the framework for the hard work that will follow", Pompeo said.
Where is the summit?
Sentosa is the largest offshore island in Singapore, its name is derived from the Sanskrit word for santosha which means 'peace'.
The Capella Hotel in Singapore is a five-star luxury base for the meeting.
The entire resort has been booked out for the event with the cheapest room costing $624 Singapore dollars ($AU614).
It is owned by the Singaporean Kwee family of the Pontiac Land Group. The hotel opened in 2009 and boasts the country's only circular ballroom with a glass-dome skylight.
How much will the summit cost?
Singapore's Prime Minister Lee Hsien Loong said the total cost of the summit would be $20 million Singapore dollars ($AU19.6 million)
Half of this is spent on security costs and personnel have been deployed around-the-clock during the summit.
Hundreds of hotel rooms have been booked for the event. Trump staying at the Shangri La hotel and Kim at the St Regis.
2500 journalists are also in Singapore, costing about $5 million Singapore dollars to accommodate, according to the Ministry of Communications and Information.
The country has built a 3-storey international media centre for the summit at the F1 Pit building.
Why is it history-making?
It is a historic meeting for both men - perhaps comparable to president Richard Nixon's 1972 visit to China, or Ronald Reagan's summit 1986 with Mikhail Gorbachev in Reykjavik.
The meeting is potentially legacy-defining - as long as they can disprove critics' fears that the meeting will be more about drama than detail.
The North has promised to give up its weapons in the past, while a long history of previous agreements has ultimately foundered.
"If there is no statement of intentions to move toward a peace treaty, if there's no statement from the North Korean side on denuclearisation, we're going to find ourselves very quickly in a very hollow summit," Ryan Hass of the Brookings Institution said.
If that happened, he added, "quickly we'll move into a space of mutual recrimination and finger-pointing about whose fault it was".
What's North Korea saying about it?
Before the talks the North's official KCNA news agency called the summit "historic", saying it would take place in a "changed era" and "under the great attention and expectation of the whole world".
Kim was expected to exchange "wide-ranging and profound views" on issues including "building a permanent and durable peace-keeping mechanism on the Korean peninsula" and "realising the denuclearisation of the Korean peninsula", it added.
Trump is expected to sit down with Fox News host Sean Hannity after the summit. The interview will also take place at the Capella Hotel.