China's exports of rare earths in May increased by 23 percent from April to 5,864.60 tons, with total exports from January to May growing by 2.3 percent year-on-year to 24,827 tons, according to data released by the General Administration of Customs on Monday.

China views its rare earths as a national security issue, not a trade one, and that’s why Beijing is unlikely to loosen controls anytime soon, experts say.

China on Saturday said it had granted approval to some applications for the export of rare earths, in a move that comes just ahead of fresh trade talks between Chinese and U.S. officials on Monday. China's strict export controls over rare earths has been a flashpoint in trade relations with the U.