North Korean leader Kim Jong-un has set off by train for Vietnam for his second summit with US President Donald Trump next week, Russia's TASS news agency has reported.
The report came hours after Vietnam announced that Kim would make an official visit in "coming days", as the Southeast Asian country prepares to host the summit with Trump on Wednesday and Thursday.
No details of the leaders' travel arrangements, or for the summit, have been officially released.
A landmark first summit between Trump and Kim in Singapore last June produced a promise by Kim to work toward the complete denuclearisation of the divided Korean Peninsula. But progress has been scant.
Kim left the North Korean capital of Pyongyang at around 5 pm (1900 AEDT) in an armoured train, TASS said, citing a North Korean diplomatic source.
North Korea's state media has yet to confirm either Kim's trip to Vietnam or his summit with Trump.
It could take Kim at least two-and-a-half days to travel the thousands of kilometres through China by train to Vietnam.
His train is expected to stop at the Vietnamese border station of Dong Dang, where he will disembark and drive 170km to Hanoi by car, the sources said earlier.
Kim is visiting Vietnam at the invitation of President Nguyen Phu Trong, who is also general secretary of the ruling Communist Party, Vietnam's foreign ministry said in a statement earlier on Saturday, but it gave no further details.
Vietnamese police have stepped up security around the border station ahead of Kim's arrival.
On February 26, Vietnam will ban traffic on the road Kim is expected to take to Hanoi from a station on the Chinese border, state media said.
The preferred location for the summit is believed to be the Government Guesthouse, a colonial-era building in central Hanoi.
The Metropole Hotel would be a backup location for the summit and Kim could possibly stay in the Melia hotel.
Some foreign media organisations received a note from Vietnam's foreign ministry prohibiting live broadcasts in and around the Melia hotel and Hoan Kiem lake in the centre of Hanoi.
The JW Marriott hotel, where Trump is widely expected to stay, will also be out of bounds to live broadcasts.
