Mr Kim appears to have changed his hairstyle on the train to Hanoi - going from a middle parting to a slicked back gel look.

One possible reason for this is that while he's in North Korea, he wants to maintain some resemblance to his grandfather Kim ll-sung, who sported a very similar hairstyle, notes BBC Monitoring. But perhaps for his overseas trips, sleeker is better? Maybe he just got bored on the long train ride?

Image source, Getty Images

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Daniel Russel, the top US diplomat for Asia until 2017, has expressed scepticism about the peace deal that may emerge today.

"A peace treaty that leaves in place the arsenal of North Korean chemical, biological, and nuclear weapons that directly threaten Americans and our allies is not much of a peace treaty."

North Korea's state broadcaster, Korean Central Television, usually only starts airing at 15:00 local time (06:00 GMT) - we'll find out later if it decides to show anything about Mr Trump and Mr Kim's meeting today.

Image source, KCTV

Hanoi is known for its talented painters and artists - and some have taken to the canvas to commemorate the summit. The woman working at the gallery selling these artworks said she'd be glad to give them to Trump and Kim for nothing, if they came by.

South Korea could justifiably feel it has the most to gain from peace on the Korean peninsula - and the most to lose if this all falls apart. So South Koreans will be watching today's events closely.

The Yonhap news agency says President Moon Jae-in - who has met Mr Kim several times now - is going to make an announcement about advancing the inter-Korean relationship on Friday.

"We will actively prepare for the new Korean Peninsula regime", he's quoted as saying.

Moon Jae-in: Caught between Trump and Kim

Mr Kim has over the past year emerged as something of an international statesman, with leaders from several countries rushing to have their moment with him.

But those who suffered under his leadership have called on the world to remember the struggle and suffering of a people under his regime.

The Metropole Hotel was once used to house foreign guests during the Vietnam war - and now it’s playing host to Mr Trump and Mr Kim.

The French colonial-era hotel has a history of hosting celebrities and dignitaries, including Charlie Chaplin who went on his honeymoon there in 1936.

Image source, Reuters

It may seem to most like a meeting of equals, but NK News' managing editor Oliver Hotham says North Korea will spin this second summit as the US paying tribute.

North Korea’s state media has praised Mr Kim for making the 4,000km (2,485 mile) trip to Vietnam, with state paper Rodong Sinmun adding that his trip had caused some of its citizens sleepless nights.

“We can’t live a moment away from our leader,” one woman told a state broadcaster. “I really miss him”.

NK News also told us they'd heard some North Koreans were giving up alcohol while he is away, in a sign of devotion.

President Trump obviously has quite a lot going on at home right now. (Stay with us, but if you want to read up on that it's here.)

Our North America editor John Sopel has been looking at what messages or developments Mr Trump needs to take home with him.

"Donald Trump is said to be in no rush. Just as well. This will take as much careful navigating as getting through Hanoi's rush-hour traffic."

Locals are capitalising on the diplomacy too. Here are just some of the summit-themed T-shirts on display around the city.

Vietnam is clearly incredibly proud to be hosting this summit. The streets are decked with US, North Korean and Vietnamese flags and a handshake symbol is everywhere. They're calling Hanoi "city of peace".

With lots of media in town, Vietnam's also seizing the moment to promote tourism and culture. There are these, for example.

If you’ve been hearing talk about North Korea’s nuclear program but have no clue what’s happening, read our (very) short guide that will bring you up to speed:

Image source, Getty Images

Kim Jong-un's position in North Korea partly depends on how he can keep his people happy, explains expert Andray Abrahamian.

More from the BBC's Laura Bicker:

"The US sanctions focus on restricting North Korea’s economic activities. They target a large list of individuals and businesses. In September 2017, President Trump also authorised the Treasury Department to block any foreign business or individual which traded with North Korea from doing business with the US. The message from the White House was - you can do business with North Korea or the US, you cannot do business with both. US presidents typically impose sanctions by Executive Order, so Donald Trump could lift or re-impose sanctions if he wishes."

Are we going to see some movement on sanctions relief? That's another thing North Korea really wants.

The BBC's Laura Bicker explains: "The effect of sanctions is difficult to judge. Altogether UN sanctions target nearly 90% of Pyongyang’s exports. The UN ban on textiles alone, North Korea’s second largest industry after coal, could cost the state around $800m annually and there are estimates the measures have already cost thousands of jobs."

Here are some earlier pictures of Mr Trump and Mr Kim having a stroll around the pool in between closed door talks.

Image source, AFP

Image source, AFP

Image source, AFP