"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?" Trump said on Twitter on Sunday.

Trump and Kim will meet in Hanoi on Wednesday and Thursday, eight months after their historic first summit in Singapore in June. At the first meeting between a sitting U.S. president and a North Korean leader, both sides pledged to work towards denuclearization of the Korean peninsula.

North Korea’s Korean Central News Agency (KCNA) confirmed Sunday that Kim Jong-un has boarded a train in Pyongyang to Hanoi for the second summit with Trump and for his first official visit to Vietnam.

Delegations of hundreds of agents of both countries are already in Vietnam to ensure security for their leaders during the summit.

In the past week, the U.S. has sent several Boeing C-17 Globemaster III aircraft to Hanoi, carrying equipment needed for the summit, including a helicopter and two cars that President Trump will use in Vietnam.

An unnamed U.S. official was quoted by Reuters as saying next week's meeting would be "similar in format to what we saw last June in Singapore... there will be an opportunity for the two leaders to see one another one-on-one" before holding meetings with their respective teams.