The North Korean leader had earlier received a red-carpet reception amid tight security following a 65-hour, 2,500-mile journey from Pyongyang in a bulletproof train.
After disembarking at Dong Dang rail station, close to Vietnam’s border with China, he walked past a guard of honour before climbing into his personal Mercedes limousine on Tuesday morning.
The car was flanked by 12 security guards, who jogged briefly alongside the vehicle as it picked up speed ahead of the last leg of the journey to Hanoi.
Mr Trump will arrive in the capital later on Tuesday for the second round of landmark talks over North Korea’s nuclear weapons programme.
Wednesday’s meeting comes eight months after their historic summit in Singapore, which hosted the first ever talks between a US president and a North Korean leader.
The US president has admitted he will enter this week’s meeting with expectations substantially lower than in June 2018, indicating on Monday that he would be “happy” to secure a continuation of Pyongyang’s suspension of nuclear and missile testing.
After last year’s summit, the US president declared there was “no longer a nuclear threat” from North Korea – a claim secretary of state Mike Pompeo later admitted was untrue.
Experts are sceptical Mr Kim will give up the nuclear weapons programme he is thought to see as his best guarantee of continued rule.
Only limited details about this week’s hastily prepared meeting have been made public. Officials in Hanoi said they had about 10 days to prepare for the meeting — much less than the almost two months Singapore had before the leaders’ first talks.
Vietnam’s authoritarian leaders mobilised a huge security operation to welcome Mr Kim, shutting long stretches of roads and locking down swathes of the bustling capital city.
Train stations were also shut down in preparation for the North Korean leader’s train passing through. Pyongyang has not said why Mr Kim did travel by air to Vietnam, but his father Kim Jong-il was believed to have feared flying.
Mr Kim's choice of transport could also be symbolic. His grandfather Kim ll-sung, North Korea's first leader, travelled by train to Vietnam and Europe.
Mr Kim’s train, heavily armoured and fitted with tinted bulletproof windows, is said to travel at an average speed of about 35 miles an hour. According to South Korean media reports, it consists of about 90 carriages and includes conference rooms, an audience chamber, satellite phones and bedrooms.
Hours before Mr Kim crossed the China-Vietnam border, footage from Japanese TV network TBS showed taking a pre-dawn smoke break at a train station in China. He was accompanied by a woman who appeared to be his sister, Kim Yo-jong, who was holding a crystal ashtray at the ready.
Roads on Tuesday were shut down from the border with China all the way to Hanoi, 106 miles away, where crowds and a pack of journalists waited for Mr Kim to arrive at the heavily guarded Melia Hotel.