The Philippines will not allow "any offensive actions" from the bases it has opened to US troops, President Ferdinand Marcos said on Monday.

Manila last week announced the locations of four more military bases it is allowing the US military to use on top of the five agreed on under the 2014 Enhanced Defence Cooperation Agreement, known as EDCA.

The deal allows US troops to rotate through and store defence equipment and supplies.

China warned last week the expanded military deal could endanger regional peace, and accused Washington of a "zero-sum mentality".

The four additional bases include sites near the hotly disputed South China Sea and another not far from Taiwan.

Marcos said China's reaction over the expanded military deal was "not surprising", but assured them the Philippines is only shoring up its territorial defence.

"We will not allow our bases to be used for any offensive actions. This is only aimed at helping the Philippines whenever we need help," Marcos told reporters.

"If no one is attacking us, they need not worry because we will not fight them."

The pact stalled under former president Rodrigo Duterte, who favoured closer ties with China.

But Marcos, who succeeded Duterte in June, has adopted a more US-friendly foreign policy and sought to accelerate the implementation of the EDCA. (AFP)