Donald Trump has said he would like to meet North Korean leader Kim Jong Un during his upcoming trip to Asia.

I would. If you want to put out the word, I'm open to it, the US president told reporters onboard Air Force One as he departed for the region, adding that he had a great relationship with Kim.

Trump made history during his first term, becoming the first sitting US president to set foot into North Korea when they last shook hands in 2019.

His trip to Malaysia and Japan will see him meet a number of world leaders including China's Xi Jinping, amid trade negotiations sparked by Trump's imposition of sweeping tariffs earlier this year.

Trump has taken an atypical approach to North Korea - a secretive communist totalitarian state largely isolated on the world stage - and its attempts at creating nuclear weapons, initially taunting Kim as a little rocket man.

The pair met face-to-face three times during Trump's previous tenure in office but failed to agree on a denuclearisation programme. North Korea has since conducted multiple tests of intercontinental missiles, its neighbours say.

Asked if he would recognise North Korea as a nuclear state, Trump told reporters late on Thursday: I think they are sort of a nuclear power... They got a lot of nuclear weapons, I'll say that.

Kim has said he was open to meeting Trump again, provided the US stopped pursuing its absurd demand for North Korea to give up its nuclear weapons.

South Korea's Unification Minister Chung Dong-young mentioned there was a considerable possibility of a meeting between the two leaders while Trump is in South Korea for the Asia-Pacific Economic Co-operation (Apec) forum.

A senior US official stated that a meeting was not in Trump's official schedule, although their last meeting in the demilitarised zone (DMZ) came off the back of an invitation by Trump on social media.

Trump's first stop will be in Malaysia, where he will attend the Association of Southeast Asian Nations (Asean) summit. He is expected to land in the South Korean city Busan on Wednesday ahead of the Apec summit.

He will meet South Korean leader Lee Jae Myung, who discussed peace on the Korean peninsula and the possibility of a Trump-Kim meeting during his visit to the White House in August.

Trump's meeting with China's President Xi comes against the backdrop of a trade war between the two nations, which has seen both sides agree to hold off on potential tariffs while seeking negotiation. However, tensions have risen after Trump proposed a significant trade levy on Chinese goods linked to restrictions on rare earth exports.