SINGAPORE - A trade war between the United States and China will affect the global economy significantly and unsettle financial markets, said Finance Minister Heng Swee Keat, who added that Singapore has to watch the developments with great caution.

Although there are frameworks under the World Trade Organisation (WTO) to settle disagreements over trade, these issues should not be escalated, he said in response to questions from reporters during a ministerial community visit on Sunday (July 8).

"I hope that all the countries which are involved in this will take very thoughtful and calibrated action to reduce the tension," he added.

After months of rhetoric, US President Donald Trump imposed 25 per cent tariffs on US$34 billion (S$46 billion) of Chinese goods last Friday - in what Beijing called "the largest trade war in economic history".

China responded by hitting back with retaliatory measures on US goods, accusing the US of violating WTO rules.

Even the party which starts the trade war is not going to benefit from it, Mr Heng noted.

The global economy is in a delicate stage of recovery after the last severe global financial crisis, he said, adding that financial markets will be looking at the trade issue with great concern.

Mr Heng also spoke on other issues during his visit to the Workers' Party-held ward of Kaki Bukit in Aljunied GRC.

On the recent property cooling measures which included raising the Additional Buyer's Stamp Duty (ABSD) by 5 percentage points, Mr Heng reiterated the importance of prices not getting "decoupled from economic fundamentals".

"I dealt with the global financial crisis. It was a very severe crisis, and it is important for us to keep markets stable and in particular, make sure that property prices do not run ahead of fundamentals," he said.

Asked about Malaysian Finance Minister Lim Guan Eng's latest remarks about the water supply agreement between Singapore and Malaysia, Mr Heng said he would not comment on the issue at this time, but stressed the importance of standing by international agreements.

On whether there has been any backlash from residents to the Goods and Services Tax (GST) hike that will kick in between 2021 and 2025, he said the tax increase "is part of our long term planning to make sure that we can look after our elderly even better".

"When I explain this to our elderly and they know that they are going to be a major beneficiary of this, I think there is much better acceptance," he added.

During his visit to Kaki Bukit, the minister also launched a voucher scheme for low- to middle-income Singaporeans.

Up to 200 needy families in the ward will soon be able to get vouchers that subsidise their expenses, under a new scheme called Kaki Bukit Cares that started this month.

The initiative allows eligible low-income households to receive $50 in vouchers monthly, for up to three months on end, said Kaki Bukit division's grassroots advisor Shamsul Kamar.

These vouchers can be used at six coffee shops, a provision shop and a supermarket in the neighbourhood.

To qualify, families have to meet two of three criteria. They have to earn a monthly household income of $3,000 or below or per capita income of $850 or less, be a Singaporean resident living in Kaki Bukit, or have received a recommendation from Mr Shamsul.

Mr Shamsul, who contested the opposition-run GRC during the 2015 general election under the People's Action Party, noted that 14 per cent of residents in the ward live in rental flats.

"There are many schemes available for low-income families, but they often require the submission of documents and for residents to meet specific criteria," he said.

In comparison, the new vouchers can be disbursed more flexibly to provide short-term relief, he added. Their eligibility will be reviewed every three months.

There are no plans yet to expand the scheme to other wards in Aljunied GRC, said a People's Association spokesman.