WASHINGTON (BLOOMBERG) - The White House wants North Korean leader Kim Jong Un to commit to a timetable to surrender his country's nuclear arsenal when he meets President Donald Trump next week in Singapore, a high-stakes summit that could last as long as two days - or just minutes.

Trump has been advised not to offer Kim any concessions, as the White House seeks to put the onus on the North Koreans to make the summit a success, one US official said. The president is determined to walk out of the meeting if it doesn't go well, two officials said.

Alternatively, Trump is toying with the idea of offering Kim a follow-up summit at his Mar-a-Lago resort in Palm Beach, Florida - perhaps in the fall - if the two men hit it off.

Other than announcing that the two leaders will first meet at 9am Singapore time June 12 at the Capella Hotel on Singapore's Sentosa Island, the White House has described no schedule for the summit.

If the first meeting goes well, there will be further events that day and perhaps even on June 13.

Trump will be joined in Singapore by Secretary of State Mike Pompeo, his Chief of Staff John Kelly and National Security Adviser John Bolton. The US delegation also tentatively includes the CIA's top Korea expert Andrew Kim; the National Security Council's point person on Korea Allison Hooker; and White House Deputy Chief of Staff Joe Hagin, who has negotiated much of the groundwork for the summit with the North Koreans.

Notably absent from Trump's delegation: Vice-President Mike Pence, who will remain in the US, and Defence Secretary James Mattis.

Mattis said on Sunday at the Shangri-La Dialogue defence conference in Singapore that North Korea will win relief from crippling US economic sanctions "only when it demonstrates verifiable and irreversible steps to denuclearisation".

Trump's Preparations

North Korea has publicly bristled at US officials' insistence that it must agree to disarm before receiving anything in return, instead calling for a step-by-step approach to ridding the Korean Peninsula of nuclear weapons.

Trump has indicated flexibility in his approach, although it's still unclear what a path to denuclearisation would look like.

Pompeo, who has travelled to Pyongyang twice since March, has prepared Trump for the summit in about eight-to-ten hours of briefings per week for several weeks, two US officials said. The CIA's Kim has usually joined him.

On Tuesday, former senators Sam Nunn and Richard Lugar briefed Trump and Pence on their lessons learnt co-sponsoring a law aimed at securing and dismantling nuclear weapons after the fall of the Soviet Union.

Typically, the president's preparations for meetings with foreign leaders are shaped by several administration officials and result in a pair of briefing books, one person familiar with the process said.

One, on customs and protocol, primarily is assembled by the State Department and shared with much of the US delegation. The other is a more exclusive document for the president that includes a biography of the foreign leader assembled by the US intelligence community.

It also sometimes includes memos from individual Cabinet members with their private assessments of the leader.

Trump's aides consider him ready for a summit in which the White House believes he holds an advantage - while 12 hours ahead of Washington, Singapore is a Westernised metropolis and will be the farthest Kim Jong Un has travelled since taking charge of his country in 2011.

Kim's Worries

US officials believe Kim is extremely worried about security at the summit and is fearful of assassination attempts, according to two people familiar with the matter.

Frustrated after the North Koreans cut off communications for about five days last month and snubbed Hagin at a preparatory meeting in Singapore, Trump cancelled the summit on May 24.

Talks resumed, however, and Kim dispatched an envoy - his spy chief Kim Yong Chol - to Washington on Friday to deliver a letter to Trump.

The letter, handwritten by Kim Jong Un in Korean, expressed the dictator's desire for the summit. Trump said later that day that the Singapore meeting was back on.

Kim Yong Chol also brought Trump a gift, and Trump reciprocated with a gift for Kim Jong Un. White House officials declined to describe either present.