China will continue to export rare earth minerals and said its export controls were for environmental protection reasons, the Chinese Foreign Ministry said on Thursday, after a government move to cut rare earth export quotas raised fresh international trade concerns.

Foreign Ministry spokeswoman Jiang Yu made the comments at a regular news briefing in Beijing.

China, which produces about 97 percent of the global supply of the metals used in the production of numerous high-tech products, cut export quotas by 35 percent for the first half of 2011 versus a year earlier, saying it wanted to conserve reserves.

China has refused U.S. requests to end export restraints on rare earths that have alarmed trade partners. Washington could complain to the World Trade Organization, which judges international trade disputes, the U.S. Trade Representative office said last week.

(Reporting by Ben Blanchard and Sabrina Mao, writing by Sui-Lee Wee; Editing by Chris Lewis)