The Chinese Embassy in Washington, responding on Monday to a U.S plan to sail within 12 nautical miles of artificial islands China has built in the South Chinaislands, said the concept of freedom of navigation should not be used as excuse for muscle-flexing.

Embassy spokesman Zhu Haiquan said the United States should "refrain from saying or doing anything provocative and act responsibly in maintaining regional peace and stability."

"Freedom of navigation and overflight should not be used as excuse to flex muscle and undermine other countries' sovereignty and security," he said.

A U.S. defense official said earlier the U.S. Navy planned to send a guided-missile destroyer within 12 nautical miles of artificial islands built by China in the South China Sea early on Tuesday.