The leader of the Democratic People's Republic of Korea (DPRK) Kim Jong Un left Pyongyang on Saturday for Vietnam, ahead of his second summit with U.S. President Donald Trump, Yonhap News Agency reported citing Russian media Tass.

The summit is scheduled for February 27 and 28. Kim will travel at least two-and-a-half days by train through China. He is expected to arrive in Vietnam on February 25.

It will be Kim's second face-to-face encounter with Trump following their first meeting in Singapore in June last year.

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

The visit by Kim Jong Un, chairman of the Workers' Party of Korea and chairman of the State Affairs Commission of the DPRK, will be made at the invitation of General Secretary of the Communist Party of Vietnam Central Committee and State President Nguyen Phu Trong, the ministry announced on its website.

Vietnamese police have stepped up security around the border station ahead of Kim's arrival.

The preferred location for the summit is the Government Guesthouse, a colonial-era building in central Hanoi, three sources told Reuters on Wednesday.

They said the Metropole Hotel would be a backup location for the summit and Kim could possibly stay in the Melia hotel.