Twenty-five Chinese military jets breached Taiwan’s defence zone on Monday, the island’s government has said, after a senior US official warned of an “increasingly aggressive” Beijing. The defence ministry scrambled aircraft to broadcast warnings to leave after Chinese jets, including 18 fighters, entered the island’s southwest air defence identification zone for a 10th straight day. The incursion – the largest in a year – came after the US secretary of state, Antony Blinken, on Sunday warned China not to attempt to change the status quo around Taiwan, saying to do so would be a “serious mistake”. Democratic, self-ruled Taiwan lives under the constant threat of invasion by China, which has vowed to one day seize the island, by force if needed. On Friday the US state department said it would make it easier for US officials to meet Taiwanese representatives, defying pressure from China. The sabre-rattling has increased since the 2016 election of Taiwan’s president, Tsai Ing-wen, who rejects the idea that the island is part of “one China”. Some analysts and US military officials have said tensions between Taiwan and China are now at their highest since the mid-1990s. Blinken told NBC’s Meet the Press on Sunday: “What we’ve seen, and what is of real concern to us, is increasingly aggressive actions by the government in Beijing directed at Taiwan, raising tensions in the [Taiwan] Straits.” He reiterated the US’s longstanding commitment to Taiwan, but he would not be drawn on whether Washington would respond militarily to any Chinese action there. “All I can tell you is it would be a serious mistake for anyone to try to change the existing status quo,” he said. Taiwan’s ageing fighter fleet has had a string of fatal accidents in recent years as its air force is kept under constant pressure by China. Last year Chinese jets made a record 380 incursions into Taiwan’s air defence zone, according to Taipei authorities.