The move follows Washington’s announcement last week of $11.1 billion in arms sales to Taiwan, the largest ever U.S. weapons package for the island, drawing Beijing’s ire.

“The Taiwan issue is the core of China’s core interests and the first red line that cannot be crossed in China-U.S. relations,” a Chinese foreign ministry spokesperson said in a statement on Friday.

“Any provocative actions that cross the line on the Taiwan issue will be met with a strong response from China,” the statement said, urging the U.S. to cease “dangerous” efforts to arm the island.