UPDATE (9 a.m. Eastern):
President Donald Trump has arrived in Vietnam for his meeting with North Korea's Kim Jong Un.
Jong Un arrived Tuesday morning (local time) in Vietnam in his heavily armored train, ahead of his two day summit with US President Donald Trump in the capital Hanoi.
The summit, the second since the two leaders met in Singapore last June, is expected to build upon their agreement to "work toward complete denuclearization of the Korean Peninsula."
Critics say that meeting -- the first between a North Korean leader and a sitting US president -- failed to produce concrete action in getting the North to give up its nuclear weapons.
After a two-and-a-half-day trip that covered about 2,800 miles overland, Kim arrived Tuesday to a red carpet welcome at 8:15 a.m. local time at the Dong Dang railway station in the border town of Dong Dang in Vietnam's Lang Song province.
There was a heavy security presence at the station from Monday, with Vietnamese soldiers and sniffer dogs patrolling the area. Camera crews gathered outside in anticipation of the arrival.
The trip is considerably more arduous from a logistical perspective than Kim's previous meeting with Trump, during which he hired a Chinese plane to travel to Singapore.
Kim's Mercedes pulled in to meet him surrounded by his North Korean bodyguards , who ran alongside the car as it pulled away.
Kim's motorcade is expected to drive the remaining 100 miles to Hanoi -- with the entire stretch of road reportedly closed to all normal traffic.
Like most things related to the North Korean leadership, Kim's exact route from Pyongyang to Hanoi has been shrouded in secrecy.
Kim's train left Pyongyang Railway Station on Saturday afternoon and passed the northeastern Chinese port city of Tianjin on Sunday, according to Yonhap News.
He reportedly passed through the central Chinese city of Wuhan at 7 a.m. on Monday local time, before reaching the Chinese side of the Vietnamese border early Tuesday morning.
North Korean Central News Agency reported Kim's departure and said the leader is accompanied by North Korea's lead negotiator in nuclear talks Kim Yong Chol, his sister Kim Yo Jong, and various other high-ranking officials.
Kim Jong Un's wife, Ri Sol Ju was not named as among his entourage.
KCNA reported that Kim will pay an "official goodwill visit" to Vietnam at the invitation of Nguyen Phu Trong, General Secretary of the Communist Party of Vietnam. On Saturday, Vietnam confirmed for the first time that Kim would make an official visit "in the coming days," according to a statement posted on the official Twitter feed of Vietnam's Foreign Ministry spokesperson.
Trump's Air Force One is scheduled to arrive in Hanoi on Tuesday night local time. The US President tweeted on Sunday that "without nuclear weapons" North Korea "could fast become one of the great economic powers anywhere in the World."
"Because of its location and people (and him), it has more potential for rapid growth than any other nation!" he wrote.
North Korea is one of the poorest countries in the world with an estimated per capita income of just $1,300 a year.
Famed family train
Images from Pyongyang on Saturday showed Kim waving to a farewell party from inside his train -- known for its green paintwork and horizontal yellow stripes.
While few details of Kim's particular train are known, it resembles the one used both by his grandfather, Kim Il Sung, and his father, Kim Jong Il, who reportedly threw lavish dinners aboard.
According to a 2009 report in South Korean newspaper Chosun Ilbo , Kim Jong Il's train was 90 carriages long and was so heavily armored, it traveled at an average speed of 60 kilometers an hour (about 37 miles mph).
"Kim's train is armored and also contains conference rooms, an audience chamber and bedrooms. Satellite phone connections and flat screen TVs have been installed so that the North Korean leader can be briefed and issue orders," the paper reported at the time.
"Before Kim's train nears the station, the power on other tracks is shut off so that no other trains can move," the report said.
Kim Jong Un used the train in January and last March, when he made a surprise visit to Beijing to meet Chinese President Xi Jingping. Images from North Korean state media show Kim and his entourage sitting on pink leather sofas in an airy white carriage.
His lengthy rail trip continues a family tradition of preferring train travel over more modern forms of transport.
In 2001, his father Kim Jong Il made a nine-day trip in a 21-car armored train from Pyongyang to Moscow to meet with Russian President Vladimir Putin.