The US-China trade war has escalated as China sanctions multiple companies in retaliation for weapons sales to Taiwan.

The US and China have been locked in a trade war, with each side taking shots at the other. The US has banned ZTE and Huawei, and urged its allies to do the same. The administration altered the Entity List and Foreign Direct Product Rule to cut Huawei from any chip suppliers that use US technology, including TSCM, one of its prime suppliers. The Trump administration is also pushing for a ban of WeChat and TikTok.

In response, China passed new regulations limiting the technologies that could be exported. In particular, the new regulations target the algorithm TikTok uses, thereby putting in jeopardy any deal that might avert a US ban by selling TikTok’s US operations to another company.

Now China has gone even further, sanctioning Lockheed Martin, Boeing Defense, Space & Security (BDS) and Raytheon over weapons sales to Taiwan.

“As China pointed out on multiple occasions, the U.S. arms sales to Taiwan severely violate the one-China principle and the three China-U.S. joint communiqués, and seriously undermine China’s sovereignty and security interests,” said Foreign Ministry Spokesperson Zhao Lijian in a press conference. “China firmly opposes and strongly condemns it.

“To uphold national interests, China decides to take necessary measures to sanction U.S. companies involved in the arms sales to Taiwan including Lockheed Martin, Boeing Defense, Space & Security (BDS) and Raytheon, as well as the U.S. individuals and entities who played an egregious role in the process.”

It’s unclear what long-term impact the sanction’s will have on the US companies. In the short term, the news caused a sharp sell-off of those specific stocks, dragging down industrial stocks in general Monday.