Choe Kang Il, deputy director for North American affairs at Pyongyang's foreign ministry, is expected to meet retired US diplomat Kathleen Stephens, according to multiple reports.

The meeting follows three days of talks between North Korean and Swedish officials in Stockholm that apparently fell short of clearing the way for a US-North Korea summit attended by both nation's leaders.

Sweden plays a key liaison role between the West and North Korea and Swedish Foreign Minister Margot Wallstrom met counterpart Ri Yong Ho at the weekend.

Trump earlier this month stunned many observers by agreeing to meet the North Korean leader following months of spiralling tensions on the Korean peninsula over Pyongyang's nuclear programme.

His response triggered a race to set a credible agenda for what would be historic talks between the two leaders.

But no specific time or venue has been set and North Korea has yet to confirm it even made the offer to meet.

Kimmo Lahdevirta, the director of American and Asian affairs at Finland's foreign ministry, told AFP that there would be a "routine meeting" Sunday of officials and academics in Helsinki on the North Korean issue.

He said the talks were "in no way connected" to Ri's Sweden visit, adding that Choe was not meeting any current US officials while in Finland.