The agreement for a second summit between Donald Trump and Kim Jong Un was a “remarkable breakthrough” for peace negotiations on the Korean peninsula, President Moon Jae-in said Monday, but he acknowledged doubts remained over denuclearisation.

The US President and North Korean leader are due to meet in Hanoi from February 27 to 28 following their landmark first summit in Singapore last June.

That meeting — the first-ever between the leaders of the US and North Korea — produced a vaguely-worded document in which Kim pledged to work towards “the denuclearisation of the Korean peninsula”.