A hotel on the Singaporean resort island of Sentosa has emerged as a highly likely venue for a historic summit between U.S. President Donald Trump and North Korean leader Kim Jong Un.

But locals say the first-ever U.S.-North Korea summit could still instead be held at the Istana, the Singapore's president's official residence, which already has security arrangements fully in place to host heads of state and other foreign dignitaries.

(Sentosa)

At Capella Singapore, the luxury hotel on Sentosa, U.S. and North Korean working-level delegations gathered earlier this week to discuss logistics and security issues related to the summit, originally scheduled on June 12, sources close to the matter said.

As Sentosa is a tiny island, linked to the mainland by a 380-meter causeway, it is easy to ensure security there during the period of the summit if it really takes place, the sources said.

When Kyodo News reporters tried to access the hotel by taxi to cover the working-level meeting, hotel employees stopped the car at one of compound's tree-ringed entrances and refused entry to anybody without a room reservation.

"Thank you for choosing the Capella hotel. But unfortunately, our rooms are fully booked. The hotel is closed," one of the staff told the reporters.

Many journalists, who covered the working-level U.S.-North Korea talks, said the hotel, designed in the shape of a figure 8, is like a fortress surrounded by wooded gardens, adding that if the Trump-Kim summit takes place there, security could be fully ensured.

"Sentosa" means peace and tranquility in Malay. A local reporter told Kyodo News that it would be "appropriate" for Trump and Kim to meet and shake hands with each other on the island.

The hotel, however, is located just outside the Universal Studios theme park and near other leisure facilities on island, which attract tourists from home and abroad.

If the summit is held there, Singapore should close the entire island for several days for security reasons, seriously impacting the local economy heavily reliant on tourism, a local Straits Times newspaper reporter told Kyodo News.

The reporter said that the Istana, located in the center of the city-sate, "is a possible location" as it often hosts foreign guests and security is always in place.

(Istana)

The majestic, colonial-era building, whose name means "palace" in Malay, is hidden away on lush wooded grounds, though its expansive compound neighbors a popular big shopping mall.

"Nobody sees the palace unless it is open to the public," a taxi driver in Singapore said. It holds open houses only five times a year -- days such as Chinese New Year, Labor Day and National Day.

On Thursday, Kyodo News confirmed more than six people, who wore uniforms, were guarding the gate of the presidential residence, with the taxi driver saying that usually, two or three people stand in front of the entrance.

There are no buildings around the Istana from which the presidential palace can be seen.

"Even if President Trump and North Korean (leader) Kim meet at the Istana, that will not surprise me," said a middle-aged female worker at a nearby Chinese restaurant.

Journalists in Singapore, meanwhile, say Trump is expected to stay at the Marina Bay Sands hotel, run by a supporter of the president, and Kim may stay at the Shangri-La Hotel, which has hosted a key security meeting in Asia every year.