KIM Jong-un last night set off on a train journey to Vietnam for his landmark second summit with Donald Trump.

The North Korean dictator, 35, was seen on state TV inspecting a guard of honour in Pyongyang station before waving from his lavish carriage.

Later, the distinctive bulletproof green-and-yellow locomotive was seen crossing into the Chinese border city of Dandong on the nearly-3,000 mile journey to Hanoi.

It is said to be stocked with vintage wines and will cater any cuisine Kim desires.

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

CHANGE IN TONE
President Trump, 72, announced the meeting in his State of the Union address to Congress earlier this month.

He said at the time: "If I had not been elected President of the United States, we would right now, in my opinion, be in a major war with North Korea.

"Much work remains to be done, but my relationship with Kim Jong-un is a good one.

"Chairman Kim and I will meet again on February 27 and 28 in Vietnam."

Trump's words marked a decisive change in tone from when he first took office amid a spate of North Korean missile tests that threatened to push the region to the brink of war.

The US President famously branded Kim "little rocket man" - while North Korean state media dubbed Trump a "dotard".

FRAUGHT TALKS
Their historic Singapore summit last June - the first between sitting US and North Korean leaders - ended without substantive agreements on the North's nuclear disarmament.

It triggered a months-long stalemate as Pyongyang sought assurance that US sanctions would be lifted in return for scrapping its nuke capability.

Kim's overseas travel plans are kept top secret.

It is expected to take more than two days for the train to make the epic journey through China to Vietnam.

Experts say Kim will seek a US commitment for improved bilateral relations and partial sanctions relief.

He will also try desperately to make as few concessions as possible on his nuclear facilities and weapons.

Few see it as likely that Kim will fully scrap his arsenal - which he may see as his strongest guarantee of survival as North Korea's leader.

NUCLEAR ISSUE
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.

But none of those steps were seen as meaningful cutbacks to the North's weapons capability.

Washington has called for more concrete steps from Pyongyang toward denuclearization before talk of lifting sanctions can begin.

Hanoi has been gearing up for the summit with beefed-up security.

Officials say the colonial-era Government Guest House in central Hanoi is expected to be the venue for the Trump-Kim meeting, with the nearby Metropole Hotel as a backup.

Streets around the area have been spruced up with flowers and the flags of North Korea, the US and Vietnam.

Workers were also putting final touches on the International Media Center.

Vietnam's Foreign Ministry says some 2,600 members of the foreign press have registered for the event.

Meanwhile, Vietnam has announced a traffic ban along Kim's possible arrival route.