North Korea is in talks with the US and Sweden to release three Americans held in the North, reports said, as diplomatic activities gathered pace ahead of Pyongyang's planned summits with Washington and Seoul.
The release of the three Korean-Americans -- all held in the North after being separately charged with unspecified "hostile acts" against the regime -- is under discussion through multiple channels almost two weeks after President Donald Trump agreed to meet the North's Kim Jong Un, reports said.
While Pyongyang has yet to confirm it even made the summit offer -- relayed by Seoul envoys who had met Kim in Pyongyang -- the stunning announcement has triggered a race to set a credible agenda for what would be historic talks between the two leaders.
Seoul-based MBC TV station reported Sunday that Pyongyang and Washington had "practically reached" a final agreement on the release of Kim Hak-song, Kim Sang-duk and Kim Dong-chul.
"They are hammering out details over the timing of the release," it quoted an unnamed South Korean diplomatic source as saying.
The negotiation was held through the North's mission to the United Nations and the US State Department -- an unofficial avenue of communication dubbed the "New York channel," the source said.
CNN said the prisoners' release was also discussed at three-day talks in Stockholm between the North's Foreign Minister Ri Yong-Ho and Swedish counterpart Margot Wallstrom that ended Saturday.
Sweden represents Washington's interests in talks with the North. It raised the issue of American detainees to "move things in the right direction," CNN quoted one source as saying.
"Any movement on the issue of these detainees would be a huge deal for the US," said the source.
Kim Dong-chul, a South Korea-born American pastor, has been detained by the North since 2015 when he was arrested for spying. He was sentenced to 10 years of hard labour in 2016.
Kim Hak-song and Kim Sang-duk -- or Tony Kim -- were both working at the Pyongyang University of Science and Technology, founded by evangelical Christians from overseas, when they were detained last year on suspicion of "hostile acts."
- Diplomatic flurry -
Reports on the detainees' possible release come amid a flurry of diplomatic activities involving Pyongyang, Seoul, Washington and its allies.
During a visit to Pyongyang by Seoul's envoys earlier this month, Kim reportedly offered to meet Trump, with the US president subsequently agreeing to talks by May although no specific time or venue has been set.
Kim also agreed to hold a summit with South Korean President Moon Jae-in next month -- the third ever between the two Koreas -- according to the envoys.
South Korean Foreign Minister Kang Kyung-wha said in an interview aired Sunday that Kim was "taking stock" after Trump's surprise decision to accept the invitation, but that a channel of communication had been established.
The Stockholm talks overlapped with another meeting among the top national security advisors of the US, South Korea and Japan.
US National Security Advisor HR McMaster, the South's Chung Eui-yong and Japan's Shotaro Yachi met in San Francisco over the weekend and vowed "close policy coordination" for the weeks ahead, Seoul's presidential office said.
They agreed that peace on the flashpoint Korean peninsula hinges on the success of the two planned summits, vowing "not to repeat the failure of the past," it said in an apparent reference to previous botched nuclear disarmament negotiations with the North.
Also on Sunday, a senior North Korean diplomat arrived in Finland for talks on peninsula issues with former officials and academics from the US and South Korea.
The sudden rapprochement comes months after the North staged its most powerful nuclear test and test-fired missiles capable of reaching the US mainland.
Kim and Trump traded colourful threats of war and personal insults, which heightened global concerns of another conflict on the peninsula once brought to ruins by the 1950-53 Korean War.