Donald Trump and Kim Jong-un will meet one-on-one at the start of their second summit in Vietnam – a detail that could raise concerns following the president’s solo meeting with Vladimir Putin when he asked for the interpreter’s notes.

That initial meeting next week in Hanoi will be followed by a meal and expanded talks with each country’s delegation, a US official has revealed.

“President Trump is looking to, after really in some respects breaking the ice in June, to talk in more depth about the kind of future North Korea could enjoy if it follows through on its commitment to final and full denuclearisation,” the official, insisting on anonymity, told reporters in a briefing call on Thursday.

The official said this was an important step toward that ultimate goal of denuclearisation.

Mr Trump was criticised by some for failing to secure any solid committment from North Korea after their first, historic meeting last June in Singapore.

Singapore Summit: historic first meeting between Trump and Kim Jong-un Show all 20 1 /20 Singapore Summit: historic first meeting between Trump and Kim Jong-un Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump and Mr Kim leave following their historic meeting AFP/Getty Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump and Mr Kim sign a document committing to peace between their nations, amongst other things EPA Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump holds up a document that both he and Mr Kim have signed AFP/Getty Singapore Summit: historic first meeting between Trump and Kim Jong-un The two leaders reach out to shake hands for the first time AP Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump and Mr Kim shake hands as they meet for the first time Reuters Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump and Mr Kim walk off stage, following their historic meeting Reuters Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump and Mr Kim take a stroll after their meeting on June 12 Reuters Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump and Mr Kim interrupt their stroll to talk to the media AP Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Kim and Mr Trump look out over a balcony at the Capella hotel, where they held their meeting on June 12 Reuters Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump takes questions at the press conference following his meeting with with Mr Kim AP Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump appreciates the crowd in the press conference following his meeting with Mr Kim Getty Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump travels to the Istana ahead of the summit with Kim Jong Un on June 12 Reuters Singapore Summit: historic first meeting between Trump and Kim Jong-un Kim Jong Un travels to the Istana ahead of the summit with President Trump on June 12 Reuters Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Kim poses for a photo with Singapore's Finance Minister Vivian Balkrishnan and Education Minister Ong Ye Kung ahead of the summit with Mr Trump Twitter/Reuters Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump shakes hands with Singapore Prime Minister Lee Hsien Loong, meeting on Monday June 11 in the Istana, Singapore's presidential palace AP Singapore Summit: historic first meeting between Trump and Kim Jong-un At a working lunch on Monday, Singapore's Prime Minister surprised Mr Trump with a birthday cake, in early celebration of his 72nd birthday later in the week EPA Singapore Summit: historic first meeting between Trump and Kim Jong-un US Secretary of State Mike Pompeo answers questions about the summit at a press briefing in Singapore on Monday, June 11 Getty Singapore Summit: historic first meeting between Trump and Kim Jong-un US President Donald Trump arrives at the Paya Lebar Air Base in Singapore on June 10, two days prior to his summit with North Korean leader Kim Jong Un Reuters Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump and Mr Kim met on Tuesday June 12 in the Capella hotel on the island resort of Sentosa, just off the south coast of Singapore AFP/Getty Singapore Summit: historic first meeting between Trump and Kim Jong-un Mr Trump boards Air Force One following the summit AFP/Getty

“In addition president Trump is looking to, after really breaking the ice with Kim in June, to talk in more depth about the kind of future that north korea could enjoy if it follows trough on its commitment to the final and full denuclearisation.”

Mr Trump announced details of his second meeting with Mr Kim doing his state of the union address last month, suggesting his personal engagement with the North Korean leader – the first by a sitting US president – had already reaped dividends.

“As part of a bold new diplomacy, we continue our historic push for peace on the Korean Peninsula. Our hostages have come home, nuclear testing has stopped, and there has not been a missile launch in 15 months,” he said.

“If I had not been elected president of the United States, we would right now, in my opinion, be in a major war with North Korea. Much work remains to be done, but my relationship with Kim Jong-Un is a good one.”

North and South Korean leaders Kim Jong-un and Moon Jae-in sign joint agreement on denuclearisation

The fact Mr Trump will initially meet the North Korean alone could trigger concerns among some. Earlier this year it was reported he had gone to “extraordinary lengths” to keep details of a 2017 conversation with Mr Putin secret from officials in own administration.

The Washington Post said after a meeting with the Russian leader at the G-20 summit in Hamburg, the US president took his interpreter’s notes and told him not to discuss the meeting with anyone.

After his meeting with Mr Kim last summer, the president was criticised by some for obtaining very little in exchange for a meeting that helped project his image on the international stage. The two men issued a joint statement that reaffirmed the North’s commitment to “work toward complete denuclearisation of the Korean Peninsula” and gave US guarantees of security to North Korea.

Yet Democrats, and others, said the agreement was light on detail. “One trip and it’s ‘mission accomplished’, Mr President? North Korea still has all its nuclear missiles, and we only got a vague promise of future denuclearisation from a regime that can’t be trusted,” congressman Adam Schiff, said at the time.

Observers hope the second summit will be more productive and that work behind the scenes may have already nailed down some details that would suggest concrete progress.

“Possible scenarios of progress include an agreement to ease some sanctions in exchange for North Korea forfeiting certain ballistic missiles or freezing nuclear production,” said Kevin Martin, president of Peace Action, a Washington DC-based non-profit organisation.