The “one China” principle is the basis for developing ties with China and no country can be an exception to this rule, Chinese Foreign Minister Wang Yi told his French counterpart.

U.S. President-elect Donald Trump has upset China by speaking with the president of self-ruled Taiwan, which China claims as its own, and casting doubt on Washington’s nearly four-decade policy of recognizing that Taiwan is part of “one China”.

Speaking with French Foreign Minister Jean-Marc Ayrault, Wang said the Taiwan issue concerns China’s sovereignty and territorial integrity, China’s Foreign Ministry said late on Thursday.

“The one-China principle is the prerequisite and basis for other countries to develop their relations with China and that when it comes to this vital issue of right or wrong, no country can be an exception,” the statement cited Wang as saying.

Wang said he appreciated Ayrault’s clear stance on the “one China” issue.

Beijing regards Taiwan as a renegade province and has never renounced the use of force to bring it under its control. China considers Taiwan independence a red line issue.

(Reporting by Ben Blanchard; Editing by Michael Perry)