The US secretary of defence has sought to reassure Japan of Washington’s commitment to the defence of the region amid ongoing denuclearisation talks with North Korea.

James Mattis met with the Japanese defence minister, Itsunori Onodera, on Friday, and told him his visit represents “just how strongly we prioritise this relationship between our two militaries.”

Japan’s defence establishment was startled by Donald Trump’s recent decision to halt what he said were “expensive” military exercises with South Korea, which Tokyo has long considered a deterrent to threats from North Korea.

Mr Mattis said even as the US is in “unprecedented negotiations” with the totalitarian state, “in this dynamic time, the longstanding alliance between Japan and the United States stands firm.

He went on to say ”there is absolute reassurance between the two of us that we stand firm” and the relationship will not be affected by the denuclearisation talks.

After their meeting, Mr Onodera said they had agreed to continue joint military exercises and reinforce the response capability of the US-Japan alliance.

Trump says media coverage of his North Korea summit 'almost treasonous'

Earlier this month, he urged the international community to keep sanctions and surveillance on North Korea, warning it has a history of reneging on agreements.

Speaking at an international security conference in Singapore, Mr Onodera said North Korea agreed to give up nuclear weapons as early as 1994, but has continued to develop them in secret and until last year threatened surrounding countries with a series of ballistic missile launches.

On Friday, he said the US and Japan must work together for the dismantlement of “all of North Korea’s weapons of mass destruction, including biological and chemical weapons and ballistic missiles of all ranges.”

Japan hosts around 50,000 US military personnel, including the largest overseas concentration of US Marines and a US Navy carrier strike group.

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 another nod to Japan’s concerns, Mr Mattis noted the blue ribbon-shaped lapel pin the minister was wearing, a reference to the 12 Japanese citizens abducted by North Korea four decades ago to train its spies.

“I note with respect the blue lapel pin you wear, and we’re with you,” Mr Mattis remarked as he sat down for talks at the defence ministry. He later said the abductee issue was “always present in our deliberations.”

Japan has argued their release should be part of the ongoing negotiations with Pyongyang.

Mr Mattis also reassured South Korea the US would maintain the current number of troops it has on the Korean Peninsula during a brief visit to Seoul on Thursday.

Speaking alongside the South’s defence minister, Song Young-moo, he read a lengthy statement reinforcing America’s “ironclad” commitment to Seoul.

He went on to say the US would “continue to use the full range of diplomatic and military capabilities to uphold this commitment.”

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However, in both Seoul and Tokyo, he defended Mr Trump’s decision to halt “war games,” saying it would help diplomats negotiate.

“This decision was taken to create space for our diplomats to negotiate strongly and increasing the prospects for a peaceful solution on the peninsula,” Mr Mattis said.

“At the same time, we maintain a strong collaborative defensive stance to ensure our diplomats continue to negotiate from a position of unquestioned strength.”