North Korea's Kim Jong-un said he will work with China to secure "true peace" on Wednesday, as Beijing seeks to take the driving seat in fast-paced diplomacy over Pyongyang's nuclear weapons.

Kim made the promise to Chinese president Xi Jinping during his third trip to Beijing since March, a visit which observers see as further helping to rebuild historic ties between the two former Cold War allies.

The North Korean leader told Mr Xi he would work with China on "opening a new future" on the Korean peninsula, according to the official Korean Central News Agency (KCNA).

The leaders discussed denuclearisation, KCNA said, while Kim was also thought to have briefed Mr Xi on his historic summit with Donald Trump last week.

The meeting in Singapore - the first between sitting leaders of the United States and North Korea - included commitments by Kim to work toward denuclearisation in exchange for US security guarantees.