US: 'ONLY TIME WILL TELL'

"Good things are happening, but only time will tell!" tweeted Trump, who is scheduled to meet Kim within weeks. In a second tweet, Trump wrote: "KOREAN WAR TO END! The United States, and all of its GREAT people, should be very proud of what is now taking place in Korea!"

CHINA: 'JOURNEY TO STABILITY'

"We applaud the Korean leaders' historic step and appreciate their political decisions and courage," Chinese foreign ministry spokeswoman Hua Chunying told a press briefing. "We hope and look forward to them taking this opportunity to further open a new journey of long-term stability on the peninsula."

JAPAN: 'WATCHING MOVES'

“I want to welcome that (talks) as a positive move toward comprehensive resolution of various issues concerning North Korea," Japanese Prime Minister Shinzo Abe told reporters. "We strongly hope that North Korea will take concrete action through this meeting and a summit between the US and North Korea.  "We will keep watching North Korea's future movements.

RUSSIA:  'VERY POSITIVE NEWS'

"This is very positive news," Russian President Vladimir Putin's spokesman told reporters. "Today we see that this direct dialogue has taken place (and) it has certain prospects," he said. "The will to seek agreement can be seen on both sides, including the most important thing -- the will to begin and continue dialogue. That is a positive fact," Dmitry Peskov said.

NATO:  'HARD WORK LIES AHEAD'

"This is a first step, it is encouraging, but we have to realise there is still a lot of hard work that lies ahead of us," Nato chief Jens Stoltenberg said at a meeting of Nato foreign ministers in Brussels.

UK: 'DON'T BE OVER-OPTIMISTIC

"I am very encouraged by what's happened. I don't think that anyone looking at the history of North Korea's plans to develop a nuclear weapon will be over-optimistic but it's clearly good news that the two meet," British Foreign Secretary Boris Johnson said in Brussels.