"Singapore was selected because they have been willing to hold it, and because they have diplomatic relations with both the U.S. and North Korea. They are one of very few countries that have relationships with both countries," a White House official told CNBC on Thursday.
The city-state of 5.6 million people is an experienced host to major summits involving high-ranking officials from around the world. In 2015, it was the chosen site for a milestone meeting between Chinese President Xi Jinping and former Taiwanese President Ma Ying-jeou.
"We did not put our hand up, but we were asked," the country's minister for foreign affairs, Vivian Balakrishnan, told reporters on Tuesday during a working visit to Washington.
"The Americans approached us first. The North Koreans subsequently came to us," he added, according to a transcript of the interview. "I think Singaporeans can be proud. Proud that we've been chosen because they know that we are neutral, reliable, trustworthy and secure."
Singapore has strict laws that limit public demonstrations. A police permit is needed to hold public assemblies in the country. A park area known as the Speakers' Corner in downtown Singapore is the only place where demonstrations can be held without a permit, but other restrictions apply: An approval must be sought and foreigners must not participate.
Trump and Kim will meet on Sentosa, a smaller island off the coast of Singapore's main island.
When CNBC asked whether limits on protests in Singapore played a role in its choice of Singapore, the White House official said Washington has "conveyed our views and believe in freedom of the press."
"We're grateful to them for hosting. [Selecting Singapore] has to do with their willingness and graciousness in hosting and the fact that the North Koreans are willing to do it there," the official added.
A Kim Jong Un impersonator from Australia who uses the name Howard X told Reuters on Friday that he was detained by Singaporean authorities upon arrival at the city's airport and asked about his "political views."
Singaporean authorities did not have immediate comment on that matter, Reuters said.
Singapore's security capabilities make it a logical choice for the event, Joshua Kurlantzick, a senior fellow for Southeast Asia at the Council on Foreign Relations, wrote in a Wednesday note.
"The city-state's diplomatic corps and security and intelligence personnel are highly respected globally and shown repeatedly that they can host a major summit without allowing any significant security or intelligence slip-ups," he said.
— CNBC's Eamon Javers contributed reporting.