Impersonators of U.S. President Donald Trump and North Korean leader Kim Jong Un hammed it up and posed for photos at a mall in Singapore on Saturday, with fans lining up to have selfies taken with the duo.

"The 'Real' Trump-Kim Summit" was held at the Bugis Junction mall on the eve of the arrival of the two leaders in the wealthy city-state for their historic summit on Tuesday.

Howard X, an Australian-Chinese in his 30s, and Dennis Alan, a 67-year-old American, mimic the two world leaders by dressing up, and even speaking and acting like them.

Howard, the Kim look-alike, donned a black Mao suit, replete with Kim's trademark hairstyle and glasses, while Trump doppelganger Alan wore a smart business suit and red tie.

"Most people can't get close to the real guys so this is the next best thing," said Howard X.

Asked about media reports that he was detained by police upon arrival at Changi Airport on Friday, he said, "I think the immigration officers wanted to intimidate me. They said not to go to Sentosa," the resort island where the summit between the two leaders will be held.

"I don't expect anything but hopefully it will go well," he said about the upcoming summit.

"Trump treasures personal relationships between people more than the policy itself so hopefully these two people will get along because they really have the same personality, really are the same person. Let's see what happens," he added.

Alan said he hoped the summit will help "lay down the framework for a lot of future talks and make the world a safer place for everybody."