China's military said it carried out more exercises near Taiwan on Monday as a group of US lawmakers visited the Chinese-claimed island and met President Tsai Ing-wen, in what Beijing said was an infringement of its sovereignty.
The five US lawmakers, led by Senator Ed Markey, arrived in Taipei on an unannounced visit late on Sunday, the second high-level group to visit following that of US House of Representatives Speaker Nancy Pelosi in early August, which set off several days of Chinese war games.
The Chinese military unit responsible for the area adjacent to Taiwan, the People's Liberation Army's Eastern Theatre Command, said it had organised multi-service joint combat readiness patrols and combat drills in the sea and airspace around Taiwan on Monday.
The exercises were "a stern deterrent to the United States and Taiwan continuing to play political tricks and undermine peace and stability across the Taiwan Strait", it added.
China's Defence Ministry said in a separate statement that the lawmakers' trip infringed on China's sovereignty and territorial integrity and "fully exposes the true face of the United States as a spoiler and spoiler of peace and stability in the Taiwan Strait".
"The Chinese People's Liberation Army continues to train and prepare for war, resolutely defends national sovereignty and territorial integrity, and will resolutely crush any form of 'Taiwan independence' separatism and foreign interference."
Neither statement gave details of the drills.
Pelosi's visit infuriated China, which responded with test launches of ballistic missiles over Taipei for the first time, and ditching some lines of dialogue with Washington, including theatre military talks and on climate change.
The latest group of US lawmakers to visit Taiwan were due to meet Tsai on Monday morning. Her office has yet to comment on that meeting.
The United States has no formal diplomatic ties with Taiwan but is bound by law to provide the democratically governed island with the means to defend itself.