The upcoming summit between the leaders of the United States and North Korea will most likely be held on Singapore's resort island of Sentosa, reliable sources told Kyodo News on Sunday.

The sources, who have knowledge of plans for the summit, said the United States has chosen Sentosa, off the southern coast of Singapore, to be the venue for the talks between U.S. President Donald Trump and North Korean leader Kim Jong Un on June 12.

However, the North Korean side has not yet given its nod to the proposed venue.

One of the hotels on Sentosa will be used for the summit.

(Singapore's resort island of Sentosa)

"Not sure of the reason for the delay in confirmation" from Pyongyang, one of the sources said, adding that logistical negotiations for the summit are still very "fluid."

"The delay could be due to the time taken for the communication between both sides," the source said. "After the United States settled on the venue, the other side needs to assess the venue and whether the personal preference of Kim has been met."

While the United States will be paying its part, Singapore as the host may have to sponsor some of the costs of organizing the summit as North Korea "has no foreign exchange and it is heavily sanctioned, which means it does not have much international currency."

Advance teams of working-level delegations from the United States and North Korea had gathered earlier last week at the Capella Singapore, a luxury hotel on Sentosa, to discuss logistics and security issues related to the summit.

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 actually takes place.

The sources said the North Korean side, especially Kim, does not trust international hotels and would prefer to stay in locally owned hotels in the city-state. For example, the Fullerton hotel, where the North Korean delegation stayed for the logistical preparations, is owned by Singaporeans who have close links to business interests in China.

If Kim stays at the Fullerton, and Trump also stays at a hotel in the city-center, both parties will likely make their way to Sentosa island for the summit.

The island's name "Sentosa" means peace and tranquility in the Malay language. The island is home to the Universal Studios theme park and several five-star hotels, a convention center and a casino.