Trump is flying from the US and is due to land at Noi Bai International Airport in the Vietnamese capital on Tuesday night.
Trump expressed optimism about his upcoming summit with Kim as he tweeted aboard Air Force One: "Heading over to Vietnam for my meeting with Kim Jong Un. Looking forward to a very productive Summit (sic)!"
Before departing for Hanoi, he also said, "We want denuclearization, and I think he'll have a country that will set a lot of records for speed in terms of an economy."
