Ignoring China's objections, US House Speaker Nancy Pelosi met with Taiwan's President Tsai Ing-wen on Wednesday. Soon Beijing started its military exercises in the South China Sea as a retaliatory gesture.
Earlier, Pelosi visited the Taiwan parliament, which made her the highest-ranking US official to visit the island in 25 years.
Beijing views the self-governing Taiwan as a breakaway territory that will one day be reunited with the mainland and warned the US against allowing Pelosi to visit.
In response to her arrival late Tuesday, China launched military exercises in six areas in the waters surrounding Taiwan. They are expected to include long-range live-fire exercises and last through Sunday.
The manouevres are seen as the biggest show of military muscle from Beijing since the 1995 Taiwan Strait crisis, when China fired missiles over Taiwan and the US dispatched two aircraft carrier groups.
The Chinese Foreign Ministry summoned the US ambassador to China, Nicholas Burns, early Wednesday to protest Pelosi's visit as a "serious provocation and violation" of the one-China principle, state newspaper Global Times reported.
China also sent 21 planes into Taiwan's air defence identification zone on Tuesday alone, the Defence Ministry in Taipei said.
Taiwan, which has 23 million inhabitants, has long considered itself independent. Taiwan has issued strong condemnation of China's plans for live fire drills in locations around the island.
Such drills "have invaded Taiwan's territorial space" and "amount to a blockade of Taiwan's air and sea space", Taiwan's military said, BBC reported.
Taiwan's President Tsai Ing-wen has also criticised the drills, saying they are an unnecessary reaction and Taiwan was committed to maintaining the status quo across the Taiwan Strait. Taiwan's Defence Ministry said its military would "counter any move that violated Taiwan's territorial sovereignty".
Beijing says foreign aircraft or ships should not enter the area while their drills are underway, BBC reported. Taiwan argues this is in breach of international law and global trade and shipping rules.
The island's military had stepped up their alertness level. Authorities would enact plans to "ensure safety and stability around the island" - a response to China's announcement to hold three days of military drills encircling the island beginning Thursday.
The Taiwanese cabinet added that citizens should feel reassured in their security.
Top US Democrat Nancy Pelosi met the Taiwan's President despite sharp warnings from China against the visit. She is expected to have lunch and then leave the island, Taiwan's official central news agency says.
The trip, which is not backed by President Biden, is the first by such a senior US official in 25 years. BBC reported.
China's army will hold military exercises in areas around Taiwan from Thursday until Sunday. But the US says there is no need to turn the visit into a crisis, with Pentagon spokesman John Kirby emphasising America supports the status quo.
(With inputs from IANS)
