Prime Minister Dr Mahathir Mohamad warned today his government would not cooperate with Singapore if it ignored concerns over a controversial land reclamation programme.

"We hope Singapore cooperates. If they act as they wish, we will also act as we wish.

"If Singapore wants us to cooperate with them, they have to cooperate with us," said Mahathir.

The premier was responding to Singapore's announcement Wednesday that it would continue to reclaim land in the narrow Tebrau Strait which separates the tiny republic from its large neighbour.

Singapore says the project is within its territorial waters, but Malaysia fears it could obstruct ships headed for ports in Johor, which are being promoted to rival Singapore's port.

Mahathir expressed disappointment over Singapore's attitude.

"I don't know. Their deputy prime minister came and said he will consider (halting) but they are still continuing, so it's a little difficult now," he told reporters here.

"We also cannot give our cooperation if they don't give their cooperation."

Fresh strain

Earlier in the month, visiting Singapore Deputy Prime Minister Lee Hsien Loong had said he would consider the effects of the reclamation works from an official Malaysian study, which has yet to be completed.

Foreign Minister Syed Hamid Albar Thursday urged Singapore not to be selfish over the project, saying it was "not right for Singapore to think about (only its own interests)".

The row has put a fresh strain on ties between the neighbours, which have been erratic since Singapore was ejected from the Malaysian Federation to become an independent state in 1965.

Other issues that have strained ties include water supplies from Malaysia to the resource-poor island state, a proposed bridge linking the countries and the use of Malaysian airspace by Singaporean aircraft.