North Korean leader Kim Jong-un has arrived in Vietnam for a summit with US President Donald Trump later this week.

The second US-North Korea summit follows a historic first round of talks last year in Singapore.

Mr Kim’s green and yellow train pulled into Dong Dang station, and he has already begun the final leg of his journey to Hanoi by car.

Ceremonial guards and flag-waving crowds lined a red carpet laid out for him at the station.

Security guards, officials and cameramen crowded Mr Kim and his party as they disembarked from the train and were ushered into a waiting car.

Mr Kim then paused in front of the crowds for a brief moment, sticking his hand out of his limousine window to wave.

Why did Mr Kim take a train to Vietnam?

The journey from Pyongyang to Vietnam took more than two days and traversed about 4000 km (2485 miles). Had Mr Kim chosen to fly to Vietnam he would have got there in a matter of hours.

As Mr Kim’s train passed through China, roads were closed and train stations shut down. Chinese social media was abuzz with road closures, traffic congestion and delayed trains.

That alone would have made it a highly symbolic move for the younger Mr Kim.

Mr Kim’s private green and yellow train has 21 bulletproof carriages and is luxurious, with plush pink leather sofas and conference rooms so the journey would not have been unduly uncomfortable.

What will Trump and Kim do in Vietnam?

Mr Trump is scheduled to arrive later on Tuesday and details of their schedule are only just becoming clear.

Mr Trump will meet Mr Kim for a brief one-on-one conversation on Wednesday evening and then they will have dinner together with their advisors, according to White House spokeswoman Sarah Sanders. On Thursday, the leaders will meet for a series of back-and-forth meetings.

Why are they meeting again?

The Hanoi meeting is expected to build on the groundwork of what was achieved at the historic Singapore summit last June.

The Singapore summit produced a vaguely worded agreement, with both leaders agreeing to work towards denuclearisation – though it was never made clear what this would entail.

Why Vietnam?

It’s an ideal location for many reasons. It has diplomatic relations with both the US and North Korea, despite once having been enemies with the US – and could be used by the US as an example of two countries working together and setting aside their past grievances.

Ideologically, both Vietnam and North Korea are communist countries – though Vietnam has rapidly developed since and become one of the fastest growing economies in Asia, all while the party there retains absolute power.