BEIJING: China on Tuesday criticised enhanced US defence ties with Singapore that include the deployment of US Navy P-8 Poseidon surveillance aircraft to the Southeast Asian city state.

A stronger US military presence does "not conform to the common and long-term interests among the regional countries," Foreign Ministry spokeswoman Hua Chuying told reporters at a daily briefing.

"So we hope the relevant side does more to enhance mutual trust among regional countries, and thus benefit the regional peace and development," Hua said.

Her comments followed the signing of an enhanced defense cooperation agreement Monday between US Defence Secretary Ash Carton and Singapore Defence Minister Ng Eng Hen.

Singapore has long provided logistical support for US military ships and aircraft, and the new agreement will take cooperation to a higher level, including in battling nonconventional threats such as piracy, transnational terrorism and cyber defence, according to a Defence Department statement.

The two officials also welcomed the inaugural deployment of a Poseidon aircraft from December 7 to 14, saying it would help with "maritime security efforts," among other areas.

Such planes form part of the US military presence in and around the South China Sea, where China has been taking increasingly robust steps to uphold its sovereignty claims against neighbors such as Vietnam and US ally the Philippines.

Those moves have included the building of new islands by piling sand on top of coral reefs, followed by the construction of harbors, airstrips and other infrastructure.

The US and others have accused China of raising tensions in an increasingly militarized region and called for an end to the island building. Beijing has rejected the accusations against it and holds that the US has no right to comment on South China Sea territorial disputes.

China is also adamantly opposed to US surveillance missions off its coastline, although the sides recently signed an agreement to avoid unexpected incidents that could lead to confrontations.