United States President Donald Trump has accepted an invitation from North Korean leader Kim Jong Un to meet, holding out hope for a cooling of tensions following months of missile tests and megaphone diplomacy.
The offer was conveyed by South Korea's National Security Adviser Chung Eui Yong, who led a delegation from Seoul to meet Mr Kim in Pyongyang earlier this week, and briefed Mr Trump at the White House on Thursday evening.
"President Trump appreciated the briefing and said he would meet Kim Jong Un by May to achieve permanent denuclearisation," Mr Chung told reporters.
Mr Trump said in a Twitter post: "Kim Jong Un talked about denuclearisation with the South Korean representatives, not just a freeze. Also, no missile testing by North Korea during this period of time."
He added: "Great progress being made but sanctions will remain until an agreement is reached. Meeting being planned!"
South Korean President Moon Jae In hailed the upcoming meeting as a "historic milestone" that could pave the way for complete denuclearisation of the Korean peninsula, and Russia and China welcomed the positive development.
"The Korean government will cherish this miraculous opportunity and make progress in a sincere, careful and steady manner," Mr Moon said in a statement.
However, analysts and officials in Asia and the US were more guarded, and urged caution.
The unprecedented summit comes as tensions eased after last month's Winter Olympics, and as Mr Kim and Mr Moon are set to meet in the truce village of Panmunjom at the end of next month.
Chinese President Xi Jinping discussed North Korea in a phone call with Mr Trump, saying China upholds using dialogue, and that he appreciated the US President's desire to resolve the issue politically, state media reported.
Singapore also welcomed the talks. A spokesman for the Ministry of Foreign Affairs said: "Singapore welcomes the recent announcement of plans for US President Donald Trump and Democratic People's Republic of Korea (DPRK) leader Kim Jong Un to meet in the near future, as well as efforts by all parties to reduce tensions on the Korean peninsula.
"We also note the DPRK's reported commitment to denuclearisation and pledge to refrain from further nuclear and missile tests. We hope that this will contribute towards lasting peace and eventual denuclearisation of the Korean peninsula."
But Japanese Foreign Minister Taro Kono said there was nothing for Pyongyang to gain until it starts to take concrete steps.
Dr Sung Yoon Lee of the Fletcher School of Law and Diplomacy said: "The stakes are very high... it is nuclear diplomacy. Trump is imprudent to take the bait."
A senior US administration official said Mr Trump was elected in part because he is willing to take approaches "very different from past approaches and past presidents".
"President Trump made his reputation on making deals," the official said. "It made sense to accept an invitation to meet the one person (Kim) who can actually make decisions instead of repeating the, sort of, long slog of the past."
But some analysts question Pyongyang's sincerity. It has not made any real concessions, said political science professor Robert Kelly of South Korea's Pusan National University. And while denuclearisation would be the ultimate concession, it was unlikely it would "suddenly do that in the next few months after 40 years trying to develop these weapons".
However, Dr Patrick Cronin of the Centre for a New American Security saw the latest move as a diplomatic breakthrough. "The April and May summits will tell us more about whether this will become a security breakthrough."
- Additional reporting by Chang May Choon in Seoul
SEE TOP OF THE NEWS