Singapore and Malaysia have postponed a meeting between their prime ministers, at which both sides were to sign an agreement on the high-speed rail project that will shorten travelling time to Kuala Lumpur to 90 minutes.

The Leaders' Retreat had been scheduled for Monday, but has been changed to a date that has yet to be finalised, officials from both sides said yesterday.

They are working out a new date.

A Malaysian newspaper report said yesterday that the signing of the agreement had been postponed owing to scheduling and administrative matters. The New Straits Times cited Minister in the Prime Minister's Department Abdul Rahman Dahlan as saying Malaysia had suggested Dec 21 as the new date.

Datuk Abdul Rahman said he met Coordinating Minister for Infrastructure and Transport Minister Khaw Boon Wan on Tuesday, and both had agreed to "fine-tune some details in the bilateral agreement".

"All other issues have been ironed out," he was cited as saying.

Singapore's Ministry of Foreign Affairs told The Straits Times yesterday that both sides are "working to hold the retreat soon".

"We are in the process of finalising the key deliverables for the Malaysia-Singapore Leaders' Retreat," its spokesman said.

Singapore's Transport Ministry said: "There has been excellent progress on the negotiations for the Kuala Lumpur-Singapore High Speed Rail Bilateral Agreement. Both Malaysia and Singapore are finalising the text and look forward to its signing at the coming Leaders' Retreat soon."

Prime Minister Lee Hsien Loong told Malaysia's Bernama news agency on Monday that both sides had made "very good progress" on the agreement.

Construction of the 350km railway is expected to start in 2018, with trains running by 2026.

Mr Lee also told Bernama that he hopes both countries can sign the agreement when he meets Prime Minister Najib Razak at the retreat.