The document signed in Singapore could mark a breakthrough, with N Korea's Kim Jong-un saying, "The world would see a major change" after his summit with US President Donald Trump.
North Korean leader Kim Jong-un and US President Donald Trump on Tuesday pledged to work toward the complete denuclearisation of the Korean Peninsula while Washington committed to provide security guarantees for a country with which the US is technically still at war.
But a joint statement signed at the end of their historic summit in Singapore gave few details on how either goal would be achieved.
"President Trump committed to provide security guarantees to the DPRK and Chairman Kim Jong-un reaffirmed his firm and unwavering commitment to complete denuclearisation of the Korean Peninsula," said the statement.
TRT World's Jon Brain brings more details from Singapore.
The DPRK – Democratic People's Republic of Korea – is the formal name of North Korea.
Trump said he expected the denuclearisation process to start "very, very quickly." US Secretary of State Mike Pompeo and North Korean officials would hold follow-up negotiations "at the earliest possible date," the statement said.
The document also made no mention of the international sanctions that have crippled North Korea's economy for pursuing its nuclear weapons programme.
Nor was there any reference to finally signing a peace treaty. North Korea and the United States were on opposite sides in the 1950-53 Korean War and are technically still at war, as the conflict, in which millions of people died, was concluded only with a truce.
But the joint statement did say the two sides had agreed to recovering the remains of prisoners of war and of those missing in action and repatriating them.
China, the third party to the truce, said it hoped North Korea and the United States could reach a basic consensus on denuclearisation.
"At the same time, there needs to be a peace mechanism for the peninsula to resolve North Korea's reasonable security concerns," China's top diplomat, State Councillor Wang Yi, told reporters in Beijing.
If the joint statement does lead to a lasting detente, it could fundamentally change the security landscape of Northeast Asia, just as former US President Richard Nixon's visit to Beijing in 1972 led to a transformation of the US relationship with China.
But Li Nan, senior researcher at Pangoal, a Beijing-based Chinese public policy think tank, said the meeting had only symbolic significance.
"It is too early to call it a turning point in North Korea-US relations," Li said.
However, the dollar jumped to a three-week top on Tuesday and Asian shares rose on news of the agreement.
Before signing what Trump described as a "comprehensive" document, Kim said the two leaders had a historic meeting “and decided to leave the past behind. The world will see a major change.”
Trump said he had formed a "very special bond" with Kim and that relationship with North Korea would be very different.
"People are going to be very impressed and people are going to be very happy and we are going to take care of a very dangerous problem for the world," Trump said.
Asked whether he would invite Kim to the White House, Trump said: "Absolutely, I will."
He called Kim "very smart" and a "very worthy, very hard negotiator."
"I learned he's a very talented man. I also learned that he loves his country very much."
“This [summit] is going to lead to more and more and more,” Trump said.
During a post-lunch stroll through the gardens of the Singapore hotel where the summit was held, Trump said the summit had gone "better than anybody could have expected."
Kim stood silently alongside, but the North Korean leader had earlier described their meeting as "a good prelude to peace."
Both men walked to Trump's bulletproof limousine, nicknamed "The Beast," and looked in at the rear seat, with Trump apparently showing Kim something inside. They then resumed their walk.
Both men had appeared cautious and serious when they first arrived for the summit at the Capella hotel on Singapore's Sentosa, a resort island with luxury hotels, a casino, man-made beaches and a Universal Studios theme park.
But with cameras of the world's press trained on them, they displayed an initial atmosphere of geniality as they met on the verandah of the Capella, a refurbished 19th-century British regimental officers' mess.
Images of geniality
After a handshake, they were soon smiling and holding each other by the arm, before Trump guided Kim to the library where they held a meeting with only their interpreters.
Trump had said on Saturday he would know within a minute of meeting Kim whether he would reach a deal.
Inside, they sat alongside each other against a backdrop of North Korean and US flags, with Kim beaming broadly as the US president gave him a thumbs up.
After initial exchanges lasting around 40 minutes, Trump and Kim emerged, walking side-by-side through the colonnaded hotel before entering a meeting room, where they were joined by their most senior officials.
Kim was heard telling Trump through a translator, "I think the entire world is watching this moment. Many people in the world will think of this as a scene from a fantasy ... science fiction movie."
Good prelude for peace
Asked by a reporter how the meeting was going, Trump said, "Very good. Very, very good. Good relationship."
Kim also sounded positive about the prospects of peace.
"We overcame all kinds of scepticism and speculations about this summit and I believe that this is good for the peace," he said. "I believe this is a good prelude for peace."
Trump was joined by Secretary of State Mike Pompeo, National Security Adviser John Bolton, and John Kelly, White House Chief of Staff, for the expanded talks, while Kim's team included former military intelligence chief Kim Yong-chol, foreign minister Ri Yong-ho and Ri Su-yong, vice chairman of the ruling Workers' Party.
As the two leaders met, Singapore navy vessels, and air force Apache helicopters patrolled, while fighter jets and an Gulfstream 550 early warning aircraft circled.
After the meetings, the two teams and other senior officials met for a working lunch, where beef short ribs, sweet and sour pork and daegu jormin, or Korean-braised cod, were served for the main course, according to the menu. That was to be followed by dark chocolate tarts, pastries and vanilla ice cream for dessert. The North Korean leader's sister and close confidante Kim Yo-jong was among the lunch party.
As the cameras captured the moment, Trump quipped, "Very nice. Getting a good picture everyone, so we all look nice and handsome and thin ... perfect."
From rhetoric to reality
Despite the opening to what could be a game-changing move by both leaders, much work needs to be done to turn their rhetoric into reality.
In Japan there was concern over the meeting and whether any deal between Trump and Kim would leave it isolated.
TRT World's Mayu Yoshida has more from Tokyo.
In the hours before the summit began, Trump expressed optimism about prospects for the first-ever meeting of sitting US and North Korean leaders, while Pompeo injected a note of caution whether Kim would prove to be sincere about his willingness to denuclearise.
US media viewed the meeting between the two leaders in a positive light. TRT World's Leone Lakhani reports from Washington.
Pompeo said the summit should set the framework for "the hard work that will follow," insisting that North Korea had to move toward complete, verifiable and irreversible denuclearisation.
North Korea, however, has shown little appetite for surrendering nuclear weapons it considers vital to the survival of Kim's dynastic rule.
Sanctions on North Korea would remain in place until that happened, Pompeo said on Monday. "If diplomacy does not move in the right direction ... those measures will increase."
The White House said later that discussions with North Korea had moved "more quickly than expected" and Trump would leave Singapore on Tuesday night after the summit, rather than Wednesday, as scheduled earlier.
Kim is due to leave on Tuesday afternoon, a source involved in the planning of his visit has said.
One of the world's most reclusive leaders, Kim visited Singapore's waterfront on Monday, smiling and waving to onlookers, adding to a more affable image that has emerged since his April summit with South Korean leader Moon Jae-in.
Trump spoke to Moon and Japan's Prime Minister Shinzo Abe, both key allies of Washington in the region, to discuss developments ahead of the summit.
"I too, got little sleep last night," Moon told his cabinet in Seoul as the summit began in Singapore.
"I truly hope it will be a successful summit that will open a new age for the two Koreas and the United States and bring us complete denuclearisation and peace."
Moon has met Kim twice in recent months and helped arrange the US-North Korean summit.
Moon said he "ardently aspires" for the success of the summit and hopes it brings complete denuclearisation and peace to the Korean Peninsula.