The president will not pay a state visit to Vietnam on this occasion, but will meet with Vietnamese top officials to discuss bilateral trade and other "important matters," Vice Minister of Foreign Affairs Le Hoai Trung told the press on Monday.

A source from the U.S. General Consulate in Ho Chi Minh City said he is expected to arrive in Noi Bai at around 9 p.m. This will be Trump's second trip to Vietnam, after the first in November 2017 when he attended the APEC summit in Da Nang and paid a state visit to Hanoi.

Before leaving the U.S., Trump had tweeted: "I will be leaving for Hanoi, Vietnam early tomorrow for a summit with Kim Jong-un of North Korea where we both expect a continuation of the progress made at first Summit in Singapore, Denuclearization?"

North Korea’s Korean Central News Agency (KCNA) had also said Sunday that Kim Jong-un has left Pyongyang by train Saturday. He is expected to arrive at Dong Dang railway station in Vietnam's Lang Son Province, which borders China, on Tuesday morning.

Vietnam's foreign ministry announced the same day that Kim will pay an official visit to Vietnam at the invitation of Party General Secretary and State President Nguyen Phu Trong, but details of the date have not been revealed yet.

Trump and Kim will meet face-to-face in Hanoi on Wednesday and Thursday next week, eight months after their historic summit in Singapore in June, the first between a sitting U.S. president and a North Korean leader, at which they pledged to work towards denuclearization of the Korean peninsula.

Trump and other senior officials in his administration have expressed hopes that the second summit will make further progress towards peace.