Washington resumed nuclear disarmament talks with Pyongyang on Sunday after Donald Trump, the US president, made history by becoming the first sitting US leader to step into North Korea, greeting the country’s leader, Kim Jong-un, with a warm handshake after months of stalled negotiations.

The historic moment had been initiated by a spur-of-the-moment tweet by Mr Trump on Saturday, when the US president invited Kim to come to the highly fortified demilitarised zone (DMZ) that separates North and South Korea to “shake his hand and say hello.”

In a dramatic made-for-TV-moment, Kim took up Mr Trump’s offer and shot down to the border zone – a 2.5-mile-wide slab of land which has been described as one of the world’s most dangerous places - to meet him shortly before 4pm.

“Good to see you again. I never expected to see you in this place,” Kim said as he greeted Mr Trump in an encounter that was beamed live around the world.

The US president then took an unprecedented step across the concrete slab that marks the border’s “military demarcation line” (MDL) and walked resolutely, shoulder to shoulder with Kim, several metres inside the North.