Duyeon Kim, a regional expert from the Korean Peninsula Future Forum in Seoul, told the BBC the summit - and in particular the document signed by the two Korean leaders - clears the way for a meeting between Kim Jong-un and Donald Trump.

"The denuclearisation language in the text, the insertion of the word complete denuclearisation, that's actually a win for President Moon, because he can take that to Washington and that helps leave the space, the political space open for President Trump to have a summit with Kim Jong-un," she said.

But any apparent commitments by the North need to be viewed with caution, she added.

"The North's track record is poor on this. They've shown time and time again that they don't live up to their promises. They show that they renege on agreements, they show that they pull various tricks and manoeuvres to get out of agreements and continue to develop and advance their nuclear weapons programme. So, if the past is a guide, I'm not optimistic."

The new US Secretary of State, Mike Pompeo, met Mr Kim in Pyongyang earlier this month.