United States President Donald Trump and North Korean leader Kim Jong Un cut short their discussions in Hanoi on Thursday, resulting in the conclusion of the nuclear summit without an agreement.
Trump said the summit ended with no agreement because he was not willing to lift all the sanctions on North Korea.
"It was about the sanctions," he told reporters after the discussions, "Basically, they wanted the sanctions lifted in their entirety, and we couldn't do that."
White House press secretary Sarah Sanders said in a statement that the two leaders had 'very good and constructive meetings' and 'discussed various ways to advance denuclearisation and economic driven concepts'.
But she went on: "No agreement was reached at this time," adding that their 'respective teams look forward to meeting in the future'.
No joint communique was issued.
In the original White House programme, a 'Joint Agreement Signing Ceremony' was scheduled as well as a working lunch for the two leaders.
In the event, both men left the summit venue without a public signing ceremony and Trump moved up his news conference by two hours, sparking doubts about the progress made at the summit.
The Hanoi summit was supposed to build on their initial historic meeting at Singapore that critics said was more style over substance.
In Hanoi, the smiles and bonhomie remained as Trump touted the 'special relationship' between the two but concrete statements were vague.
From the outset, Trump had appeared to downplay expectations of an immediate breakthrough in nuclear talks, saying he was in 'no rush' to clinch a rapid deal and was content if a pause in missile testing continued.
As in Singapore, the two men put on a show of bonhomie, appeared to share jokes in front of reporters.
Looking relaxed but appearing to say little, they indulged in a poolside stroll on Thursday around the gardens of the luxury Metropole Hotel.
In apparently unprecedented scenes, Kim answered unscripted questions from foreign reporters, saying that he would welcome the establishment of a US liaison office in Pyongyang, which would be a step on the way to diplomatic normalisation.
The Pyongyang strongman is looking for relief from sanctions imposed on the North because of its weapons programmes, which saw tensions soar in 2017 before a wave of detente.
He said there were 'people who hold a sceptical view of our meeting' but pledged to seek 'great, ultimately good results'.
Before the summit, there was talk that there could be a political declaration ending the 1950-53 Korean War which finished technically with an armistice rather than a peace treaty.
There were also hopes Kim could pledge to destroy North Korea's decades-old Yongbyon nuclear complex, which has long been at the heart of Pyongyang's atomic development but remains shrouded in secrecy -- and North Korea has promised to mothball it twice before.