China summoned the U.S. charge d’affaires in Beijing to protest the U.S. administration’s authorization of $1.83 billion arms sales to Taiwan and said it would impose sanctions on the firms involved, China’s state news agency Xinhua reported.

“Taiwan is an inalienable part of China’s territory. China strongly opposes the U.S. arms sale to Taiwan,” Xinhua quoted Vice Foreign Minister Zheng Zeguang, who summoned U.S. charge Kaye Lee, as saying.

Xinhua said Zheng described the U.S. sales authorization announced on Wednesday as going against international law and basic norms of international relations and said that they “severely” harmed China’s sovereignty and security.

“To safeguard our national interests, China has decided to take necessary measures, including imposing sanctions against the companies involved in the arms sale,” Zheng said.