The armored train carrying Kim and his entourage reached the Dong Dang railway station in the northern mountainous province of Lang Son around 8 a.m. after a long trip from Pyongyang.

He was accompanied by Kim Yong-chol, a key negotiator in talks with the U.S., and his sister Kim Yo-jong.

"I had gone through a journey of more than 3,000 kilometers to Vietnam and thank the country for a warm and enthusiastic welcome," Kim said, as described by Minister, Chairman of the Government Office Mai Tien Dung, who greeted the North Korean leader in Dong Dang.

Kim and his entourage arrived at the five-star Melia Hotel on Ly Thuong Kiet Street in Hanoi's Hoan Kiem District around 11 a.m.

He will meet with his U.S. counterpart Donald Trump on Wednesday and Thursday. Their second summit takes place in Hanoi eight months after the first one in Singapore last June. At the historic meeting, the first between a sitting U.S. president and a North Korean leader, both sides pledged to work towards denuclearization of the Korean peninsula.

Nearly 3,000 international reporters from 200 news agencies in 40 countries and territories in the world have flocked to Vietnam to cover the meeting alongside around 550 Vietnamese reporters.

Later, Kim is scheduled to pay his first official visit to Vietnam at the invitation of Party General Secretary and State President Nguyen Phu Trong.

North Korea was one of the earliest countries to establish diplomatic relations with Vietnam in 1950, after China and the Soviet Union.

It also sent hundreds of military pilots to Vietnam to support the country during the Vietnam War, trained hundreds of students in the 1960s and 1970s, and also supported Vietnam with cement, steel, fabrics, medicine and fertilizers.

Between 1994 and 2012, Vietnam also sent multiple rice donations as well as cash relief to North Korea.

Vietnam-North Korea relations have been established and cemented at the highest level. In 1957, President Ho Chi Minh visited North Korea and the late North Korean Premier Kim Il-sung visited Vietnam twice.