US reportedly ponders sailing along 12-mile territorial limit with navy ships

Beijing expressed "serious concern" on Wednesday over a reported Pentagon plan to send military ships and aircraft into areas near South China Sea reefs and demanded that Washington issue an immediate clarification.

"We request the parties concerned to speak and act in a cautious manner, not to take any risky or provocative actions, and to maintain regional peace and stability," Foreign Ministry spokeswoman Hua Chunying said at a news conference in Beijing.