BEIJING - China will never accept the Philippines' illegal seizure of the Ren'ai Reef, an area over which China has indisputable sovereignty, a Foreign Ministry spokeswoman said Monday.

"China will never accept the Philippines' illegal seizure of the Ren'ai Reef in any form. We urge the Philippines not to take any action that may complicate the situation," spokeswoman Hua Chunying said at a daily press briefing.

Hua's comments came after Philippine Defense Secretary Voltaire Gazmin  said the Philippines was free to undertake any activity in the Ren'ai Reef without notifying China.

Hua recalled how a Philippine warship illegally landed on the beach of the Ren'ai Reef of China's Nansha Islands in 1999, claiming it had been stranded.

Since then, China has repeatedly demanded that the Philippines tow the warship, but the Philippines has cited "technical reasons" for its failure to do so, Hua said.

"The Philippines' actions violated the Declaration on the Conduct of Parties in the South China Sea," Hua said, adding that Philippine warship's landing on the beach is illegal.

Hua urged the Philippines to honor its commitments and make efforts to safeguard the peace and stability of the South China Sea and promote regional cooperation.