North Korea leader Kim Jong Un is travelling to Vietnam for his second summit with US president Donald Trump, state media confirmed.

Mr Kim was accompanied by Kim Yong Chol, who has been a key negotiator in talks with the US, and Kim Yo Jong, the leader’s sister, the North’s official Korean Central News Agency reported.

TV footage and photos distributed by the North’s state-run news agency showed Mr Kim inspecting a guard of honour at the Pyongyang station before waving from the train.

South Korea US North Korea Summit
The second summit between US president Donald Trump and Kim will be held in Hanoi (Lee Jin-man/AP)

The Trump-Kim meeting is due to take place on Wednesday and Thursday in Hanoi.

Their first summit last June in Singapore ended without substantive agreements on the North’s nuclear disarmament.

It also triggered a months-long stalemate in negotiations as Washington and Pyongyang struggled with the sequencing of North Korea’s nuclear disarmament and the removal of US-led sanctions against the North.

Vietnam Summit Kim
Kim Jong Un salutes while reviewing troops at Pyongyang Station before leaving (Korean Central News Agency/AP)

Mr Trump sought to manage expectations for the meeting.

He tweeted on Sunday that he expected it to be a “continuation of the progress made at first Summit in Singapore”. He added: “Denuclearization?”

Mr Trump added that Mr Kim knew that “without nuclear weapons, his country could fast become one of the great economic powers anywhere in the World”.

Mr Kim’s overseas travel plans are routinely kept secret. It could take more than two days for the train to travel thousands of miles through China to Vietnam.

Vietnam’s foreign ministry announced on Saturday that Mr Kim would pay an official goodwill visit to the country “in the coming days” in response to an invitation by president Nguyen Phu Trong, who is also the general secretary of Vietnam’s ruling Communist Party.

Vietnam Summit
People ride motorcycles past a poster featuring the upcoming second summit between the US and North Korea in Hanoi (Minh Hoang/AP)

In his forthcoming meeting with Mr Trump, experts say Mr Kim will seek a US commitment for improved bilateral relations and partial sanctions relief while trying to minimise any concessions on his nuclear facilities and weapons.

While Mr Kim wants to leverage his nuclear and missile programme for economic and security benefits, there continue to be doubts on whether he is ready to fully deal away an arsenal that he may see as his strongest guarantee of survival.

Last year, North Korea suspended its nuclear and long-range missile tests and unilaterally dismantled its nuclear testing ground and parts of a rocket launch facility without the presence of outside experts, but none of those steps were seen as meaningful cutbacks to the North’s weapons capability.

While North Korea has repeatedly demanded that the United States take corresponding measures, including sanctions relief, Washington has called for more concrete steps from Pyongyang toward denuclearisation.