China is warning the United States of potentially “disastrous consequences” if House Speaker Nancy Pelosi visits Taiwan this week. The Chinese Foreign Ministry’s warning came as Pelosi traveled to Singapore and Malaysia as part of a tour of Asia that includes plans to become the highest-ranking U.S. official to visit Taiwan in a quarter-century.

Zhao Lijian: “If Speaker Pelosi visits Taiwan, it would grossly interfere in China’s internal affairs, seriously undermine China’s sovereignty and territorial integrity, wantonly trample on the 'One China' principle, seriously threaten the peace and stability across the Taiwan Strait, and severely damage China-U.S. relations. … We would like to warn the United States again that China is fully prepared for any eventuality. The Chinese People’s Liberation Army will not sit back.”

In response, Pentagon spokesperson John Kirby warned China against using Pelosi’s visit as a pretext to increase military activity around the Taiwan Strait. The U.S. Navy currently has four warships positioned in waters east of Taiwan, including the nuclear aircraft carrier, the USS Ronald Reagan.