China on Monday accused the United States of trying to "stir up trouble" by sending two US destroyers near disputed South China Sea islands.
The guided-missile destroyers USS Spruance and USS Preble sailed near the Beijing-claimed Spratly Islands earlier Monday as part of what Washington calls "freedom of navigation operations", Chinese foreign ministry spokeswoman Hua Chunying told a daily press briefing.
The US is "determined to stir up trouble in the South China Sea, create tension and undermine peace", Hua said.
She urged the US to cease the "provocative actions".
The sail-bys were conducted as both sides prepared for crucial trade talks in Beijing this week, seeking to avoid an all-out trade war between the world's two biggest economies.
Beijing asserts nearly all of the South China Sea as its territorial waters, while Taiwan, the Philippines, Brunei, Malaysia and Vietnam all claim parts.
The US and its allies periodically send planes and warships near South China Sea islands and reefs claimed by Beijing to signal their right under international law to pass through the waters, invariably angering China.
In mid-January, US and British warships conducted their first joint military exercises in the South China Sea since Beijing began building bases and air strips on islands.
Another US warship, USS McCampbell, sailed within 12 nautical miles (22 kilometres) of the Paracel Islands chain -- north of the Spratly Islands -- on January 7 during a previous round of trade talks between the two countries.
Just a day after that operation, Chinese state broadcaster CCTV reported that Beijing had deployed an anti-ship ballistic missile known as the DF-26 -- with a range of 3,000 to 4,000 kilometres -- to the country's northwest.