Donald Trump has said the US will stop joint military exercises with South Korea, saying it will save "a tremendous amount of money" and noting the war games are "very provocative", in what appears to be a major concession to North Korea following his summit with Kim Jong-un.

Speaking in a press conference after Mr Kim left Singapore, the US president said the "war games are very expensive", adding that the US pays "a big majority of the expenses for them".

He complained that the US flies bombers from Guam to South Korea for "six or seven hours" for the exercises, saying he "knows a lot about planes" and that was "a long time for these big massive planes to be flying to South Korea to practice and then drop bombs all over the place". Mr Trump owned an airline, Trump Shuttle, from 1989 to 1992.

Mr Trump said his second motivation for stopping war games with South Korea was that it was inappropriate now that talks had begun with North Korea.

"I think it is very provocative," he said. "You have a country that is right next door."

Mr Trump appeared to suggest that he had not yet discussed stopping the war games with South Korea itself, saying it was something "we have to talk to them about".

South Korea's presidential office said in a statement that it was trying to establish what Mr Trump meant by his announcement. A Blue House spokesperson told NPR: "At this moment, the meaning and intention of President Trump's remarks requires more clear understanding."

In a glowing statement which did not mention the issue of war games, South Korea's president Moon Jae-in said he wanted to write "new history" with North Korea, and praised Kim Jong-un for attending the Singapore talks.

"Leaving dark days of war and conflict behind, we will write a new chapter of peace and cooperation," Mr Moon said in a statement released by his office. "We will be there together with North Korea along the way."

Mr Trump's comments on the expense of the joint exercises risks opening up yet another rift with an established ally. He said: "South Korea contributes but not 100 per cent, which is certainly a subject that we have to talk to them about also, and that has to do with the military expense and also the trade.

"So we're doing that. We actually have a new deal with South Korea in terms of the trade deal but we have to talk to them. We have to talk to many countries about treating us fairly."

The comments echo Mr Trump's previous complaints about Nato countries failing to pay their way for the military alliance, and his falling-out with G7 leaders in Canada over trade links.

Earlier, Mr Trump and North Korea's Mr Kim concluded an extraordinary nuclear summit Tuesday with the US president pledging unspecified "security guarantees" to the North and Kim recommitting to the "complete denuclearisation of the Korean Peninsula."

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

Mr Trump acknowledged that the timetable for denuclearisation is long, but said, "once you start the process it means it's pretty much over."

Mr Trump sidestepped his public praise for an autocrat whose people have been oppressed for decades. He added Otto Warmbier, an American once detained in North Korea, "did not die in vain" because his death brought about the nuclear talks.

Mr Trump said Mr Kim accepted his invitation to visit the White House at the "appropriate" time.