BEIJING -- Chinese Defense Ministry strongly objects to the illegal entry of a US warship into China's waters off the Nansha Islands, said a ministry spokesperson Friday.

Wu Qian said in a statement that missile frigates Huaibei and Fushun of the Chinese Navy were immediately sent to identify the US warship, warn and expel it.

The USS John S. McCain illegally entered the waters near the reef in South China Sea earlier on Thursday. China has sovereignty of the Nansha Islands and its adjacent waters.

The US military forces intrusion under the guise of "freedom of navigation" will intensify regional militarization and may result in maritime or air accidents, said Wu.

"Such provocation will only drive China to improve its defense capacity," Wu added.

Chinese Foreign Ministry also protested US activity on Thursday.

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