At a time of political tensions over U.S. air strikes in Syria and sabre-rattling by North Korea, impersonators of President Donald Trump, his predecessor Barack Obama and Pyongyang leader Kim Jong Un brought welcome laughs to the streets of Hong Kong.

Traffic stopped as people, some in town to attend a rugby tournament, swarmed around the trio to take pictures in a downtown shopping district.

On a day when Trump was meeting Chinese president Xi Jinping in Florida with North Korea's nuclear threat high on the agenda, Trump's double hammed it up with the hermit kingdom's leader.

Kim's impersonator meanwhile kept a stern face and warned the crowds clamouring for a selfie to stop or he'd send them to a labour camp.

He was later pictured sitting with the two U.S. 'presidents'.

"Wow, I have to say that it's a great honour to sit between Obama and Donald Trump," said Kim impersonator Howard X, with a head of slick black hair and chubby cheeks.

"Let me just tell you, as a great leader, the greatest leader, Donald Trump is such a blast."

Obama impersonator Reggie Brown, sporting custom-made prosthetic ears, said he was happy for all the love.

"I think the world is missing Obama now because (of) our current president back in the United States," said Brown, who flew in from Chicago.

Also from Chicago, 66-year-old musician and Trump impersonator Dennis Allen said he wanted to offer comic relief in tumultuous political times.

"I am not Donald Trump, people have said for years that I look like Donald Trump. And I've used the way that I look ...to make people laugh. And whether or not criticisms of Donald Trump are true or not, a lot of the humour about him is funny," he said.