The destroyers' transit on Monday took place as officials in Washington and Beijing negotiated trade talks.
The US delegates and their counterparts began preliminary talks in the Chinese capital on Monday, before higher-level discussions led on the US side by Trade Representative Robert Lighthizer and Treasury Secretary Steven Mnuchin on Thursday and Friday.
Guided-missile destroyers USS Spruance and USS Preble entered the waters without permission from China, foreign ministry spokeswoman Hua Chunying told a daily news briefing in Beijing.
Brunei, Indonesia, Malaysia, the Philippines, Taiwan, and Vietnam also have territorial claims in the region.
China has lashed out at the United States in the wake of another "freedom of navigation" exercise conducted by the U.S. Navy in the South China Sea, accusing Washington of undermining "peace" and "security".
The USS Spruance and USS Preble sailed within 12 nautical miles of the Spratly Islands as part of what the US Navy calls a "freedom of navigation operation", CNN reported.
'China has indisputable sovereignty over islands in the South China Sea, including the Second Thomas Shoal, Mischief Reef, and the adjacent waters, ' Hua said.
The objective was "to challenge excessive maritime claims and preserve access to the waterways", as well as to show that the United States "will fly, sail, and operate wherever global law allows", Cmdr.
China and the United States have repeatedly traded barbs in the past over what Washington says is Beijing's militarization of the South China Sea by building military installations on artificial islands and reefs.
Shortly after that operation, China accused the U.S. of trespassing in its territorial waters - and said it had deployed missiles "capable of targeting medium and large ships".
The Chinese foreign ministry on Monday said the People's Liberation Army Navy sent vessels to track the USA warships sailing near the Spratlys and warned them to leave the area.
Last year, China added surface-to-air missiles to the contested island, one of three that the Chinese military fortified in 2018.
It has claimed the U.S. is responsible for ratcheting up war fears in the region by sending warships and military planes close to territory China believes it is entitled to.
During a South China Sea freedom-of-navigation operation in September, a Chinese destroyer challenged a US vessel to a showdown, forcing the US Navy ship off course and risking a deadly collision.