The Chinese Embassy in Manila said on Tuesday that the United States should stop “provoking confrontation” amid the presence of Chinese ships in waters Beijing insists are its own.

“The United States is not a party to the South China Sea issue. Fanning flames and provoking confrontation in the region will only serve the selfish interests of [an] individual country and undermine the regional peace and stability,” the Chinese embassy said over Twitter and tagging the official account of the US Embassy in Manila.

The Chinese Embassy made the statement after the US said it was backing the Philippines’ protest over the presence of numerous Chinese vessels in local waters.

China and the Philippines “are sovereign and independent countries,” the Chinese embassy added in a separate tweet.

“We have the will, wisdom and ability to properly handle relevant issues through bilateral channels,” it said.

The Philippines filed a diplomatic protest on Sunday against the presence of more than 200 Chinese ships at Julian Felipe Reef in the West Philippine Sea, which is within the country’s exclusive economic zone (EEZ).

On early Tuesday, the US embassy said Chinese boats have been mooring in the area for “many months in ever-increasing numbers, regardless of the weather” and accused China of using its maritime militia “to intimidate, provoke, and threaten other nations, which undermines peace and security in the region.”

The Philippines has already demanded China to “promptly withdraw” its fishing vessels from the area.

In a strongly-worded statement, the Department of Foreign Affairs (DFA) stressed that “Julian Felipe Reef in the Kalayaan Island Group lies in the Philippines’ Exclusive Economic Zone.”

“We reiterate that the continued deployment, lingering presence and activities of Chinese vessels in Philippine maritime zones blatantly infringe upon Philippine sovereignty, sovereign rights, and jurisdiction,” it said.

The DFA said Manila has been “assiduously protesting the illegal and lingering (swarming) presence of Chinese fishing vessels and maritime assets in the said areas.”

Despite this, China continued its “infringements and tolerance” that are contrary to its commitments under international law and the Asean-China Declaration on the Conduct of Parties in the South China Sea.

It called on Beijing to “faithfully honor” its obligations as a State Party to the 1982 United Nations Convention on the Law of the Sea (UNCLOS) as well as respect the “final and binding” 2016 Arbitral Award in the South China Sea, which invalidated Beijing’s nine-dash line claim in the strategic waters.

The Philippine Coast Guard initially reported that around 220 Chinese fishing vessels, believed to be manned by Chinese maritime militia personnel, were sighted moored in line formation at the Julian Felipe Reef as early as March 7.

On Monday, the Armed Forces of the Philippines confirmed that about 183 Chinese vessels are in the same area.