China said Monday it will impose new sanctions on U.S. defense contractors Raytheon Technologies and Lockheed Martin due to their arms sales to Taiwan, stepping up a feud with Washington over security and Beijing’s strategic ambitions.

Foreign Ministry spokesperson Wang Wenbin announced the move at a daily press briefing, citing a newly passed Anti-Foreign Sanctions Law that took effect in 2021. It was in response to a $100 million deal approved by the U.S. for maintenance of Taiwan’s missile defense systems by the two companies.

“China once again urges the U.S. government and relevant parties to . . . stop arms sales to Taiwan and sever military ties with Taiwan,” Wang said.

“China will continue to take all necessary measures to firmly safeguard its sovereignty and security interests in accordance with the development of the situation,” he said without giving any details.

Taiwan is a democratically self-governed island that communist-ruled China claims as its own territory. The two sides split amid civil war in 1949.

The U.S. has no formal relations with Taiwan but is its main ally. It has increased weapons sales in recent years, angering China with the sales. U.S. law requires the government to ensure Taiwan can defend itself.

Beijing regularly pressures American companies to try to influence U.S. policy.

In October 2020, Beijing also announced sanctions against Raytheon and other defense contractors and “relevant American individuals.” A day later, the State Department said it had notified Congress of plans for a $2.37 billion sale of Harpoon attack missiles to Taiwan.

It’s unclear what penalties, if any, were imposed. U.S. weapons or military aircraft sales to Taiwan in 2010, 2015 and 2019 drew similar threats of sanctions.

China maintains that U.S. arms sale to Taiwan violates its so-called “one-China principle” and provisions of agreements between Beijing and Washington.

Tensions over Taiwan have been mounting as Beijing has stepped up military activity around the island to try to force concessions from the pro-independence administration of President Tsai Ing-wen. The Communist Party also is using the Chinese mainland’s growing economic weight to pressure other governments to cut diplomatic and unofficial ties with Taiwan.

Raytheon, Boeing, Lockheed Martin and other defense industry giants face controls on sales to China of military and dual-use technologies that have both defense and commercial applications. But they also have major civilian businesses and China is a huge market for aviation, among other industries.