North Korean leader Kim Jong-un departed for Hanoi by train on Saturday for a summit with US President Donald Trump, a news report said.

Kim's train left Pyongyang around 5 p.m. local time and is expected to travel through China all the way to Vietnam, Tass news agency reported from Pyongyang, citing an unidentified source. 

Kim and Trump are set to hold their second summit on Feb. 27-28.

The report said that the train will travel around 4,500 kilometers to Hanoi, which will take over 48 hours.

Earlier, the Vietnamese foreign ministry tweeted that Kim will make an "official friendly visit" to Vietnam "in the coming days."

 North Korean media have yet to report on Kim's departure. Nor they have reported on his upcoming summit with Trump.

Speculation has been swirling about what transportation Kim will use in traveling to Hanoi. 

Flying on a state jet, codenamed "Chammae-1," was originally considered the most likely option, but the possibility of a train trip gained significant traction after a senior North Korean official preparing in Hanoi for the leader's trip visited a train station near the border with China.

Kim used a rented Chinese plane to travel to Singapore for his first summit with Trump last June. He arrived at the summit venue two days ahead of the historic meeting. 

A Chinese hotel near the border with North Korea earlier stopped receiving reservations for this weekend, in a sign that the North's leader Kim could travel to Vietnam by train for his second summit with Trump.

In their June summit, Kim and Trump agreed to complete denuclearization of the Korean Peninsula in exchange for security guarantees from the US.

Next week, they are expected to focus on concrete denuclearization steps by the North and "corresponding" measures by Washington possibly including easing sanctions and improving bilateral relations. (Yonhap)