World Bulletin / News Desk

South Korea, China and Japan will hold a trilateral summit in Tokyo next week, Seoul announced Tuesday, the latest move in a diplomatic whirlwind centred around North Korea.

It follows a historic and headline-grabbing summit between Moon and the North's leader Kim Jong Un last Friday. They vowed to pursue denuclearization and a peace treaty to formally end the 1950-53 Korean War, setting the mood for Kim's much-anticipated face-to-face encounter with US President Donald Trump.

But analysts have urged caution, warning that similar previous pledges have come to nothing, and that the North has yet to make clear what concessions it is willing to make with its nuclear weapons and ballistic missiles.

All three of the neighbours are deeply involved with North Korea -- the South as its neighbour, key US ally Japan as a sometime target for its threats, and China as its key diplomatic backer and business partner.

Friday's summit, in which Kim and Moon exchanged smiles, handshakes and warm words in front of the world's cameras, was a marked contrast to the tensions of last year.

The North staged its most powerful nuclear test to date and launched missiles capable of reaching the US mainland as Kim and Trump traded threats of war and personal insults, sparking global security fears.

The thaw between the Koreas, triggered by the Winter Olympics in the South, has repercussions for the geopolitics of the region. 

Japan has long maintained a hardline position on negotiations with Pyongyang but has found itself left on the sidelines.

With concerning growing in Tokyo over whether it should change tack, a hawkish Abe expressed a willingness to meet Kim -- a message which Moon relayed to the North's leader during the summit. 

Kim said in response he was "willing to talk to Japan any time", Moon's office said on Sunday, adding the South's leader would be "happy to build a bridge" between the two nations. 

But Moon's trip to Tokyo will be the first visit by a South Korean leader to Japan in more than six years, with relations between the two US allies marred by disputes over history and territory.