Singapore has been chosen as the venue for the US-North Korea summit, a location that mostly favors the US side, Chinese observers said on Thursday.

"The highly anticipated meeting between Kim Jong-un and myself will take place in Singapore on June 12th. We will both try to make it a very special moment for World Peace!" US President Donald Trump tweeted on Thursday evening.

The location and time of the summit has been agreed, but with more details to come in the next few days, The Guardian reported.

Singapore, as a gateway city-state between Asia and the West, would assure Trump of his security with a US military presence. It is also located "not too far" from Pyongyang, which makes it marginally acceptable to both sides, Wang Junsheng, a research fellow on East Asian Studies at the Chinese Academy of Social Sciences in Beijing, told the Global Times on Thursday.

Such a location posed challenges to the North Korean leader Kim, said Lü Chao, a research fellow at the Liaoning Academy of Social Sciences.

"North Korea, although having an embassy stationed in the Southeast Asian city-state, shares no special or intimate ties with Singapore and Kim would have to give up his most familiar and reliable special train to reach the site," Lü told the Global Times on Thursday.

A flight from Pyongyang to Singapore covered over 4,700 kilometers, Lü noted, which would seem the outer limit of a charter flight from Pyongyang. It might be more feasible for Kim to lay over in a Chinese city to refuel his jet, he said, or even lease a Chinese plane.

The long distance would also test the North Korean leader's communication with his capital city, he noted.

The meeting would be the first ever between a sitting US president and a North Korean leader.

The diplomatic atmosphere has improved greatly after Kim released US captives and pledged to freeze nuclear testing and abolish a nuclear test site, Wang said.

However, one should not overlook the fact that mutual trust between the two sides is still next to non-existent and there is a big political gap when the two sides get down to actual negotiations, he said.

US objectives for the summit were described by US Secretary of State, Mike Pompeo, as the immediate "permanent, verifiable and irreversible dismantling of North Korea's weapons of mass destruction program."

North Korea has been less definite and rather vague about its own negotiating position.

It remains difficult to predict what detailed terms Pyongyang will put on the table to achieve its goal of a security assurance from the US for its government, Wang said.

The coming summit won't resolve the denuclearization issue once and for all, Lü indicated.

"Topics will likely include how the US will verify the process, what access the US inspection team will have and what the US will offer North Korea in economic compensation for giving up for good its nuclear program," Lü said.

Trump welcomed three Americans who had been held prisoner in North Korea back home on Thursday, thanking its leader Kim for their release and sounding upbeat about the planned summit, Reuters reported.

Newspaper headline: Trump: Summit in Singapore