WASHINGTON • On the day that their talks in Hanoi collapsed last month, US President Donald Trump handed North Korean leader Kim Jong Un a piece of paper that included a blunt call for the transfer of Pyongyang's nuclear weapons and bomb fuel to the United States, according to a document seen by Reuters.

Mr Trump gave Mr Kim both Korean and English-language versions of the US position at Hanoi's Metropole hotel on Feb 28, according to a source familiar with the discussions, speaking on condition of anonymity.

It was the first time that Mr Trump himself had explicitly defined what he meant by denuclearisation directly to Mr Kim, the source said.

A lunch between the two leaders was cancelled the same day.

While neither side has presented a complete account of why the summit collapsed, the document may help explain it.

The document's existence was first mentioned by White House national security adviser John Bolton in television interviews he gave after the two-day summit.

Mr Bolton did not disclose in those interviews the pivotal US expectation contained in the document that North Korea should transfer its nuclear weapons and fissile material to the US.

The document appeared to represent Mr Bolton's long-held and hardline "Libya model" of denuclearisation that North Korea has rejected repeatedly.

It probably would have been seen by Mr Kim as insulting and provocative, analysts said.

Mr Trump had previously distanced himself in public comments from Mr Bolton's approach and said a "Libya model" would be employed only if a deal could not be reached.

The idea of North Korea handing over its weapons was first proposed by Mr Bolton in 2004. He revived the proposal last year when Mr Trump made him national security adviser.

The document was meant to provide the North Koreans with a clear and concise definition of what the US meant by "final, fully verifiable, denuclearisation", the source said.

After the summit, a North Korean official accused Mr Bolton and Secretary of State Mike Pompeo of "gangster-like" demands, saying Pyongyang was considering suspending talks with Washington and may rethink its self-imposed ban on missile and nuclear tests.

The English version of the document, seen by Reuters, called for "fully dismantling North Korea's nuclear infrastructure, chemical and biological warfare programme and related dual-use capabilities; and ballistic missiles, launchers and associated facilities".

Aside from the call for the transfer of Pyongyang's nuclear weapons and bomb fuel, the document had four other key points.

It called on North Korea to provide a comprehensive declaration of its nuclear programme and full access to US and international inspectors; to halt all related activities and construction of any new facilities; to eliminate all nuclear infrastructure; and to transition all nuclear programme scientists and technicians to commercial activities.

The summit in Vietnam's capital was cut short after Mr Trump and Mr Kim failed to reach a deal on the extent of economic sanctions relief for North Korea in exchange for its steps to give up its nuclear programme.

The first summit between Mr Trump and Mr Kim, which took place in Singapore in June last year, was almost called off after the North Koreans rejected Mr Bolton's repeated demands for them to follow a denuclearisation model under which components of Libya's nuclear programme were shipped to the US in 2004.

Seven years after a denuclearisation agreement was reached between the US and Libya's leader Muammar Gaddafi, the Americans took part in a Nato-led military operation against his government and he was overthrown by rebels and killed.

Last year, North Korea officials called Mr Bolton's plan "absurd" and noted the "miserable fate" that befell Colonel Gaddafi.

After North Korea threatened to cancel the Singapore summit, Mr Trump said in May that he was not pursuing a "Libya model" and that he was looking for an agreement which would protect Mr Kim.

The Hanoi document was presented in what US officials have said was an attempt by Mr Trump to secure a "big deal" under which all sanctions would be lifted if North Korea gave up all of its weapons.

Ms Jenny Town, a North Korea expert at the Washington-based Stimson Centre think-tank, said: "If the US was really serious about negotiations they would have learnt already that this wasn't an approach they could take."

"It's already been rejected more than once, and to keep bringing it up... would be rather insulting. It's a non-starter and reflects absolutely no learning curve in the process," she said.

REUTERS