With just days to go before his long-awaited second meeting with Kim Jong-un, US President Donald Trump on Sunday thanked China for its help setting up the summit in Vietnam aimed at ridding North Korea of nuclear weapons.
"The last thing China wants are large scale nuclear weapons right next door," Trump wrote in a series of tweets in which he praised President Xi Jinping for being "very helpful in his support" of the talks.
Trump also suggested Kim "realises … that without nuclear weapons, his country could fast become one of the great economic powers anywhere in the World" and has "potential for rapid growth".
At the same time, Vietnam's no-nonsense communist authorities were pulling out all stops to ensure this week's high-profile talks take place without glitches, with the summit venues buzzing with activity amid high security.
As diplomats tried to finalise the agenda of the meeting, Pyongyang engaged in trademark diplomatic sabre rattling - accusing the American leader's domestic political opponents of "plotting to disrupt" the summit.
State news agency KCNA said the Democratic Party was among those trying to throttle the peace talks.
It added that the US would "never be cleared of security threats" if there were no firm results from the summit - the second meeting between the two leaders in eight months.
The Hanoi summit aims to build on the historic meeting in Singapore last June where they signed a vague communique on denuclearisation.
Vietnam is expecting Kim - who is travelling from Pyongyang across China by rail - to arrive early on Tuesday, with Trump's Air Force One likely to touch down in Hanoi soon after.
Kim's luxurious armoured train passed the port city of Tianjin on Sunday morning then headed south towards Dong Dang, a Vietnamese town bordering Guangxi province.
From there, the North Korean leader is expected to travel to Hanoi by road.
Travelling with him were his sister Kim Yo-jong and senior aides, including envoy Kim Yong-chol.
Hundreds of security personnel from both sides arrived in Hanoi over the weekend, local media reported. At the JW Marriott hotel, where Trump is expected to stay, nearly a dozen uniformed Vietnamese security personnel were seen on patrol.
There were similar scenes at the nearby Melia hotel, where Kim and his entourage are likely to stay.
The local VN Express newspaper said Kim's bodyguards and North Korean reporters were given police escorts from Not Bai International Airport to the luxury hotel.
Kim Chang-son, the North Korean official tasked with overseeing protocol matters for the summit, was seen visiting another hotel - the Metropole Hanoi.
He was reportedly spotted at the conference and business centre, suggesting the third hotel could serve as the venue for the talks. That would mirror the summit in Singapore, where the two leaders stayed in separate hotels and held talks at the luxurious Capella Hotel on Sentosa.
In a sign of how serious Vietnam is taking its hosting duties, authorities will deport an Australian-Chinese Kim impersonator, after briefly detaining him and a Trump lookalike over the weekend.
Howard X told the South China Morning Post he would be taken to the airport by police on Monday.
"The police/immigration department has purchased a ticket for me to leave," he said via text message.
Russell White, the Trump impersonator "has been granted to stay but [is] not allowed to make any more public appearances," Howard X said.
As with Singapore, Vietnamese authorities have set up an international press centre to cater to the thousands of journalists expected to give the summit blanket coverage.
The city was given a taste of the media circus to come as pockets of the press gathered near the three hotels.
Lamp posts in these parts of tree-lined Hanoi have been decorated with flags of the US, North Korea and Vietnam above a handshake sign.
Additional reporting by John Power
This article was first published in South China Morning Post.