Updated

China says a controversial proposal to sell a Chinese missile defense system to U.S. ally and NATO member Turkey should not be politicized.

Foreign Ministry spokeswoman Hua Chunying said Friday the deal constituted "normal arms trade cooperation." She said it should be viewed objectively, and that such a normal commercial competition should not be politicized.

Hua's comments come one day after the U.S. ambassador to Turkey told reporters that the U.S. had concerns about the Chinese system's compatibility with NATO's missile and air defense systems.

Turkey's announcement last month that it would begin talks with a Chinese supplier on the deal worth $3.44 billion surprised many and created tensions between Turkey and its NATO allies.

China's system is competing with those from the U.S., Russia and an Italian-French consortium.