Voters have handed Singapore's long-time ruling party a landslide election victory, offering Prime Minister Lawrence Wong a clear mandate to navigate the trade-orientated Southeast Asian nation through economic upheaval sparked by looming US tariffs.

Wong's People's Action Party took all but 10 seats in the 97-seat unicameral legislature with a total of 65.57 percent of the more than 2.4 million votes cast in the island state in Saturday's polls.

"Singaporeans gave the PAP a strong mandate to govern," Wong told a news conference hours after the official results were announced.

"The results will put Singapore in a better position to face this turbulent world," he said, adding they were a "clear signal of trust, stability and confidence in your government".

Wong was facing his first major test against a rejuvenated opposition and had urged voters to offer him a strong show of support amid the global economic uncertainties brought on by US President Donald Trump's tough tariffs policy.

The PAP, which has steered the country to prosperity during its decades in power while being criticised for suppressing dissent, was always expected to easily retain a clear majority in the legislature.

Though its dominance had been increasingly challenged by a more vocal electorate over the years, the vote saw the PAP's popularity climb as compared with 2020 elections.

Popular after leading Singapore's Covid task force, Wong took over last year from his predecessor Lee Hsien Loong, the son of founding premier Lee Kuan Yew, who ruled the island state after its break-up with Malaysia in 1965. (AFP)