US Secretary of State Anthony Blinken said on Friday that any Chinese action in attacking Taiwan would have "terrible consequences".
Speaking at a news conference, he expressed hope that Chinese leaders would be very cautious about not escalating the crisis over the Taiwan Strait.
"China is working to change the situation in Taiwan, and the United States is firmly committed to making sure the island can defend itself," Blinken said.
Asked what the US response would be if China invaded Taiwan, he said:
We have been very clear over the years that we are committed to Taiwan's defense, and we continue to live up to that commitment.
Beijing considers Taiwan a part of China, and considers US moves and arms sales to Taiwan a violation of its sovereignty and contrary to the "one China" policy. However, the United States is effectively supporting the island by sending ships to the Strait of Taiwan and providing military assistance to Taiwan, and Beijing has repeatedly objected to this. However, UN member states, including the United States itself, do not recognize Taiwan as an independent state.