China’s embassy in Manila accused the United States on Tuesday of driving a wedge between the Philippines and Beijing, deploring Washington’s “unfounded accusations” that it said sought to stir up trouble in the South China Sea.

The South China Sea has become one of many flashpoints in the testy relationship between China and the United States, with Washington rejecting what it calls unlawful territorial claims by Beijing in the resource-rich waters.

Beijing was reacting to a December 19 statement by US State Department spokesperson Ned Price voicing concern over the reported “escalating swarms” of Chinese vessels in the disputed waterway and an incident involving a floating piece of rocket.

Price said China’s actions “reflect continuing disregard for other South China Sea claimants and states lawfully operating in the region”. He reiterated that the United States stands by the Philippines in upholding rules-based international order.

In a statement, China’s embassy in Manila said it was “only natural for neighbours to have differences”, but added:

“The US keeps meddling in the South China Sea disputes and trying to drive wedges between countries in the region, creating tensions and harming regional peace and stability.

“What the US has done is not to help anyone but to serve its own geopolitical interests,” it said.

China claims vast swathes of the South China Sea that overlap with the exclusive economic zones of Vietnam, Malaysia, Brunei, Indonesia and the Philippines. Trillions of dollars in trade flow every year through the waterway, which also contains rich fishing grounds and gas fields.

The Philippines last week expressed “great concern” over the “reported swarming” of Chinese vessels in a reef and shoal inside its exclusive economic zone.

That came a few days after the foreign ministry filed a diplomatic protest over a Chinese coastguard ship which the Philippine military said used force to retrieve a piece of rocket floating in the ocean that was being towed by a Philippine vessel in the South China Sea.

China has denied it forcefully grabbed the object, which it said last month was debris from the casing protecting the nose cone of a spacecraft launched by Beijing.