Pyongyang told us it's ready to work constructively: Vladimir Putin

Russia's President Vladimir Putin, after talks with China's President Xi Jinping in Beijing, said recent contacts with North Korea confirmed Pyongyang's readiness for constructive work.

"Russia and China are interested in the peace and stability of the Korean peninsula," he said.

Earlier, according to reports North Korean leader Kim Jong-un is expected to fly into Singapore's Changi airport on Sunday ahead of a high-stakes summit with US President Donald Trump, a source involved in the planning of the trip said on Friday.

Pictures of US military aircraft at nearby Paya Lebar air base, including a white-topped helicopter commonly used for transporting high-ranking US officials, were published in a newspaper on Friday.

Talks between the leaders on June 12 are expected to centre on ending the North's nuclear weapons and missiles programmes in return for diplomatic and economic incentives.

Changi airport directed Reuters' query to the Civil Aviation Authority of Singapore. The Aviation Authority did not immediately have comment.

Neither delegation has made its travel plans public.

Earlier, Singapore has said all the preparations, including security and logistic arrangements, for the June 12 US President Donald Trump and North Korean leader Kim Jong-un meeting are well in hand and expressed hope that there will be a positive outcome from the summit.

Singapore designated a special event area of the Sentosa island tourist resort for Tuesday's historic summit, which is expected to be covered by over 2,500 journalists from across the world.

"No, we did not put our hand up, but we were asked. And in this case, both the North Koreans and the United States felt that we were an appropriate venue," Foreign Affairs Minister Vivian Balakrishnan said during a visit to Washington on Tuesday.

"I think Singaporeans can be proud ... that we've been chosen because they know that we are neutral, reliable, trustworthy and secure," said Balakrishnan, adding that it was the Americans who approached Singapore first.

He assured that Singapore is ready to host the summit and "do our part" for world peace."I can say with confidence that all the preparations, logistics and security, the diplomatic arrangements, are all well in hand," Singapore media quoted the Minister as saying.

He expressed hope that there will be a positive outcome but cautioned that one meeting will not "unlock the entire situation on the Korean Peninsula".

Balakrishnan is visiting Pyongyang on Thursday at the invitation of his North Korean counterpart Ri Yong Ho, just ahead of the summit.

Singapore authorities are working, along with the Americans, to ensure very tight security.The summit will see Singapore at the peak of security , said Dr Graham Ong-Webb of the S Rajaratnam School of International Studies.

Strict security measures will be enforced around Shangri-La Hotel and The St Regis which have been selected for Trump and Kim's stay in Singapore. Security will also be very tight on Sentosa island. The Capella Hotel on the Island will be the venue for the meeting.

In 2006, Singapore deployed all security resources, including the Armed Forces as well as 26,000 national servicemen for the International Monetary Fund-World Bank meeting.

The Sentosa Development Corporation (SDC) has assured locals and tourists that it will be business as usual at the island's various unique leisure offerings. The island receives some 50,000 visitors daily.