Singapore’s Lee, who is in the US to attend the United Nations General Assembly, was quoted as saying after the signing in New York that the pact reflected “very good cooperation in defence matters” between the countries. Trump said the US had a “extraordinary relationship” with the city state and its leader.

Collin Koh, a Singapore naval and military expert, said the agreement showed the US viewed Singapore as a “primary security partner”.

Despite a strong military relationship, the two countries do not refer to each other as “allies”. Neither do defence officials refer to US facilities in Singapore as American bases.

US Navy ships including nuclear submarines and aircraft carrier groups are frequent visitors to the city state’s Changi Naval Base – which serves as a refuelling and resupply point for American forces in the Western Pacific.

From 2013, the city state started hosting rotationally deployed US littoral combat ships and later state-of-the-art P-8 Poseidon spy planes.

Koh said the Trump administration was building on former president Barack Obama’s flagship “pivot to Asia” strategy that aimed to concentrate US forward deployed forces in Asia rather than the Atlantic.

“[The agreement] also demonstrates its continued emphasis on retaining a viable US military presence in the region and locking in its security commitments,” said Koh, a research fellow at the S. Rajaratnam School of International Studies.

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Said Koh: “Mainly, [the pact] facilitated continued American security commitments, which enabled a peaceful and stable environment in the uncertain post-cold war environment, hence allowing regional countries to focus on socioeconomic development without having to devote disproportionately more resources into military build ups.”

Koh said China – which is embroiled in a geostrategic and trade tussle with the US – was likely to be “wary” of this development, but he saw this as “inevitable”.

William Choong, a senior fellow at the International Institute for Strategic Studies, said the renewal of the agreement reflected a desire for stability on behalf of Singapore and the US.

For the US, the deal granted continued access to a “very vital hub” in Southeast Asia – made all the more important after America’s relinquishing of bases in the Philippines in the 1990s, Choong said.

Meanwhile, Singapore and other trade-reliant countries would benefit because the US presence would guarantee the security of shipping routes, he said.

Choong said Beijing would understand Singapore’s position.

“I don’t think [the Chinese] necessarily agree with it, but I think they have gotten used to the fact that Singapore holds these [US] vessels,” he said.

“The Chinese will not look at this in a positive light, but I don’t think they will come all guns blazing either. It’s a natural progression.”

Singapore has long maintained that its strong strategic and economic relationship with the US does not mean it is taking sides with Washington against its Asian neighbour.

Singapore, China deepen defence ties, plan larger military exercises

Lee Kuan Yew, the late Singaporean independence leader and father of the current prime minister, once said he had no objections to both the US and China one day having logistics bases in his country.