TAIPEI (Taiwan News) — China is crying foul and accusing the U.S. of “endangering” peace and stability in the Taiwan Strait after an American reconnaissance plane flew through the strait on Monday (Feb. 27).

The Eastern Theater Command of the People’s Liberation Army (PLA) said it closely monitored the P-8A Poseidon maritime patrol and reconnaissance plane as it flew through the Taiwan Strait, according to Reuters. “The U.S. side’s actions deliberately interfered with and disrupted the regional situation and endangered peace and stability in the Taiwan Strait. We firmly oppose this,” it said in a statement.

“Theater forces remain on high alert at all times and resolutely defend national sovereignty and territorial integrity,” it added.

The U.S. Navy 7th Fleet on Monday said of the P-8A Poseidon transit that “The United States will continue to fly, sail, and operate anywhere international law allows including within the Taiwan Strait.” Adding that by “operating within the Taiwan Strait in accordance with international law, the United States upholds the navigational rights and freedoms of all nations.”

“The aircraft’s transit of the Taiwan Strait demonstrates the United States’ commitment to a free and open Indo-Pacific,” the statement said.

Meanwhile, Taiwan’s Ministry of National Defense said the P-8A had flown in a southerly direction through the waterway, Reuters reported. Taiwanese forces tracked the U.S. aircraft during its transit and noted the situation was “normal.”

China has greatly stepped up military action around Taiwan in recent years, in addition to sending PLA aircraft into Taiwan’s air defense identification zone on an almost daily basis.