
A foreign ministry spokesman said the agreement was fundamental and guaranteed by both governments in the 1965 Separation Agreement registered with the United Nations.
“Both sides must comply fully with all the provisions of these agreements,” the spokesman said.
In an interview with Bloomberg, Mahathir said the water issue was something that his administration “needs to settle”.
“We will sit down and talk with them, like civilised people,” he said.
Mahathir’s remarks came weeks after he announced the scrapping of the multibillion-dollar high-speed rail (HSR) project to connect Singapore and Kuala Lumpur, in a deal agreed by Singapore Prime Minister Lee Hsien Loong and former prime minister Najib Razak.