Malaysian Foreign Minister Saifuddin Abdullah has hit back at his Singaporean counterpart Vivian Balakrishnan, saying recent criticisms by Dr Balakrishnan on Malaysia's bid to review the 1962 Water Agreement were "reckless".

"First, he accused Malaysia of not respecting the 1962 agreement by saying we can no longer review it after 25 years," Mr Saifuddin said in Parliament on Tuesday (March 12), according to Malaysian media.

"So I don't understand what English is used by the Singaporean Foreign Minister to interpret it in such a manner," he said in response to a question by lawmaker Wan Junaidi Tuanku Jaafar - a former minister of natural resources and environment - on the terms of reference for the water agreement discussion.

Mr Saifuddin also slammed Dr Balakrishnan for what he said was a "below the belt" attack on Malaysia's governance. "That is a malicious accusation, it is hitting below the belt," said Mr Saifuddin.

Malaysian Prime Minister Mahathir Mohamad had sparked the latest sharp exchange of words by saying last month that "rich" Singapore had been benefiting from "poor" Malaysia on the water issue, and urged Johor to speak up against the 1962 Water Agreement.

The water issue came under the spotlight at the debate in Singapore's Parliament on the Foreign Affairs Ministry's budget earlier this month.

Dr Balakrishnan said then that the 1962 Water Agreement is not about who is richer or poorer.

"It is about the fundamental principle of respecting the sanctity of agreements," he said, adding that Dr Mahathir had used "strong, emotive words, no doubt intended to rouse public opinion".

Under the 1962 Water Agreement, which expires in 2061, Singapore is entitled to draw up to 250 million gallons a day (mgd) of raw water from the Johor River at three sen per 1,000 gallons.

Johor is entitled to buy 5 mgd of treated water from Singapore at 50 sen per 1,000 gallons. Singapore has said this price is heavily subsidised and below the cost of treating the water.

Singapore has, in practice, been supplying 16 mgd of treated water at Johor's request.

Mr Saifuddin said on Tuesday that Malaysia has subsidised Singapore a total of RM2.4 billion by selling raw water to the Republic based on prices agreed upon in the 1960s.

"This is at a minimum rate, if you want to measure it from the period of the agreement.

"And as you mentioned, we are selling (raw water) at such a cheap price and we are buying it at an expensive rate," Mr Saifuddin said in reply to Datuk Seri Wan Junaidi.

Mr Saifuddin said Malaysia and Singapore agreed to discuss reviewing the agreement when Tun Dr Mahathir visited the Republic last November.

"Singapore's Prime Minister had agreed to discuss the matter, as such the attorneys-general of both countries met for the first discussion.

"My officers and I followed up so we are already on the second phase of discussion, looking at the price modality, the period and other related matters," said Mr Saifuddin.

In response to another MP's question on what the government would do should Singapore continue "to be adamant and not review the agreement", Mr Saifuddin said the government needs to ensure that the country, especially Johor, has ample water supply before it takes any action.

"We need to work on zero dependency on water from Singapore," he said.

"If they no longer want to negotiate, then we will bring it to the international arbitration and when we reach such a level, I hope the lawmakers here will give us the support to do so."