China firmly opposes the US fleet's muscle flexing actions in the South China Sea and its attempts to militarize the region, Chinese Ministry of National Defense spokesperson Ren Guoqiang said at a routine press conference on Thursday.
He said satellite images show the US aircraft carrier USS Ronald Reagan was cruising in South China Sea waters, and Chinese naval vessels were seen nearby.
"We urge the US side to respect the safety concerns of countries in the region and contribute to the peace and stability of the South China Sea, Ren said.
Military observers told the Global Times that US naval forces often make an appearance in the area during major festivals in China.
The US guided-missile destroyer USS Wayne E. Meyer was reported to have illegally entered the territorial waters of China's Xisha Islands during this year's Mid-Autumn Festival.
During February's Chinese New Year, two US naval vessels sailed into waters adjacent to the Ren'ai Reef and Meiji Reef near China's Nansha Islands.
The seven "glorious" decades of People's Republic of China's history have shown that little tricks will never affect the development of China and Chinese military, Ren told the Global Times.
"China's military, as always, will resolutely perform its responsibilities and duties and safeguard the country's sovereignty and security," Ren said.