China has been particularly unhappy with U.S. support for Taiwan.
U.S. President Joe Biden angered China last week by appearing to signal a change in an American policy of "strategic ambiguity" on Taiwan by saying the United States would become involved militarily if China were to attack the island. U.S. officials said there had been no change in policy, according to Reuters.
In a statement, the People's Liberation Army Eastern Theatre Command said the combat "readiness patrol" had happened around Taiwan in recent days and was "a necessary action against U.S.-Taiwan collusion".
"Recently, the United States has frequently made moves on the Taiwan issue, saying one thing and doing another, instigating support for Taiwan independence forces, which will push Taiwan into a dangerous situation," the command added.
Taiwan is part of China and Chinese troops continue to strengthen military training and preparations to "thwart" interference from external forces' and actions by those who support Taiwan independence, it said.
Separately, Chinese Foreign Ministry spokesperson Zhao Lijian on Wednesday slammed the visit of US Senator Tammy Duckworth to Taiwan to build ties between the two sides as a violation.
Zhao cited the visit of the Democratic senator from Illinois as a blatant violation of the internationally-accepted one-China policy, warning that the Chinese nation would "take strong measures" to safeguard its sovereignty and territorial integrity.