China said on Thursday it had sent fighter jets to monitor and warn a U.S. Navy patrol aircraft that flew through the Taiwan Strait.

China claims sovereignty over democratically-governed Taiwan, and says it has jurisdiction over the narrow waterway. Taiwan and the United States dispute that, saying the Taiwan Strait is an international waterway.

Earlier on Thursday, the U.S. Navy's 7th fleet said the P-8A Poseidon maritime patrol and reconnaissance plane, which is also used for anti-submarine missions, flew through the strait in international airspace.

"By operating within the Taiwan Strait in accordance with international law, the United States upholds the navigational rights and freedoms of all nations," the Navy said, adding that the aircraft's transit demonstrates the United States' commitment to a "free and open Indo-Pacific".

China's military described the flight as "public hype", adding it had sent fighters to monitor and warn the U.S. plane.

"Troops in the theatre are always on high alert and will resolutely defend national sovereignty and security as well as regional peace and stability," the Eastern Theatre Command of the People's Liberation Army said in a statement.

Taiwan's defence ministry said the U.S. aircraft had flown in a northerly direction through the strait and stuck to its median line. Taiwan's forces kept watch the situation was "as normal", the ministry added.

China stages almost daily military activities of its own in the Taiwan Strait and seas and skies around Taiwan.

The United States last announced a Poseidon mission through the strait in July.