On Tuesday evening, US House of Representatives Speaker Nancy Pelosi arrived in Taipei, Taiwan, the highest-level US visit to the island in 25 years.
Pelosi is on an Asia tour with plans to visit Singapore, Malaysia, South Korea and Japan. Her Taiwan visit was unannounced but anticipated.
Pelosi seeks to promote the Indo-Pacific Economic Framework, a trade partnership designed to counter China's trading dominance in the region surrounding China's waters.
China considers Taiwan part of its territory and condemned the visit. The Chinese military has been put on high alert in response to Pelosi's visit, the defence ministry said.
On Tuesday morning, several Chinese warplanes flew close to the median line dividing the Taiwan Strait before leaving later in the day.
The Chinese military also announced joint air and sea drills near Taiwan and test launches of conventional missiles in the sea east of Taiwan.
Despite the absence of any official diplomatic relations with Taiwan, the US is required by law to provide the island with the means to defend itself.
Four US warships, including the aircraft carrier USS Ronald Reagan, were stationed in waters east of Taiwan on routine deployments.
