The Chinese navy asked the US vessels to leave after they entered waters adjacent to Gaven and Chigua reefs in the Spratly Islands, which Beijing calls Nansha, the foreign ministry said.

The move comes on top of trade tensions as President Donald Trump said Sunday he would raise tariffs on $200 billion in Chinese goods on Friday because talks were moving "too slowly".

"The relevant actions of the US warships violated China's sovereignty and undermined peace, security and good order in the relevant sea areas," ministry spokesman Geng Shuang said at a press briefing.

"The Chinese side expresses strong dissatisfaction and resolute opposition" to the operation, Geng added, noting that the ships had entered "without permission".

The US Navy regularly conducts "freedom of navigation operations" to challenge Beijing's vast claims in the sea.

Beijing has built artificial islands and military installations in the sea, including on the Spratlys.

China claims nearly all of the sea, though Taiwan, the Philippines, Brunei, Malaysia and Vietnam all claim parts of it.

Geng said the situation in the sea was "constantly stabilising" due to the "joint efforts" of Beijing and the Association of Southeast Asian Nations.

"Under such circumstances, China urges the US to stop such provocative acts, to respect China's sovereignty and security interests, and respect the efforts of regional countries to maintain peace and stability in the South China Sea," he said.

"At the same time, China will continue to take all necessary measures to safeguard national sovereignty and safeguard peace and stability in the South China Sea."