The Chinese military has said that it carried out a “combat readiness patrol” in the sea and airspace surrounding Taiwan, which China claims as its own territory.

The People’s Liberation Army Eastern Theatre Command stated in a statement that the exercises took place recently and were “a necessary step” against what it called “US-Taiwan cooperation.”

“Recently, the US has made repeated manoeuvres on the Taiwan problem, saying one thing and doing another, encouraging support for Taiwan independence forces, which will push Taiwan into a perilous scenario,” the command added in a statement released on Wednesday.

The largest intrusion by Chinese aircraft into Taiwan’s Air Defense Identification Zone (ADIZ) since January was recorded this week, with 30 planes, the majority of which were fighter jets, flying into the southwest of the ADIZ.

Tammy Duckworth, a US Senator, was visiting the island at the time of the event.

Beijing has “lodged solemn representations” with the US about her travel, according to Foreign Ministry spokesperson Zhao Lijian.

According to the sources, Zhao said at a press conference on Tuesday afternoon, “We urge relevant US politicians to earnestly adhere to the one-China principle, and immediately stop official exchanges with Taiwan in any form and refrain from sending any wrong signals to the ‘Taiwan independence’ separatist forces.”

“China will continue to take strong measures to protect China’s sovereignty and territorial integrity.”

In a press briefing, Zhu Fenglian, a spokesperson for the State Council’s Taiwan Affairs Office, said it was “extremely dangerous” for the US to “connive in the separatist activities performed by Taiwan secessionists.”

Taiwan, officially known as the Republic of China (ROC), is located 161 kilometres (100 miles) from the mainland Chinese shore.