China on Monday threatened to crack down on companies selling arms to Taiwan after the US gave the green light to a $300 million deal to bolster defenses on the island, which Beijing claims, AFP and Agerpres reported.

Washington announced on Friday that it has authorized the sale of defense military equipment to Taiwan, which lives under the threat of a Chinese invasion.

The decision comes as Taiwan, which Beijing considers a province but does not control, holds presidential elections next month.

“We are taking retaliatory measures against companies that sell arms to Taiwan,” said Wang Wenbin, a spokesman for China’s foreign ministry, who was asked to comment at a news conference.

The spokesman did not elaborate on what the measures would entail, nor did he provide details on the timing or the companies that may be targeted.

The Chinese government promises “decisive” measures against Taiwan

“China will take firm and decisive measures to protect its sovereignty and territorial integrity,” Wang insisted. The issue of Taiwan is very sensitive in China.

Beijing says the island of 23 million people has been ruled since 1949 by a rival regime close to the US. Taiwan is a major point of tension between the world’s two leading economies.

Chinese authorities regularly raise their reservations about any US decisions perceived as supporting the island’s formal independence.

In September, Beijing imposed sanctions on US defense industry giants Lockheed Martin and Northrop Grumman over arms sales to Taiwan.