BEIJING - The Philippines' seizure of Ren'ai Reef in the South China Sea is unacceptable to China, a Foreign Ministry spokeswoman said Friday.

Spokeswoman Hua Chunying said at a regular press briefing that China's determination and will to safeguard its national sovereignty is unswerving.

China has indisputable sovereignty over the Nansha Islands and its surrounding waters, which include Ren'ai Reef, she said.

The comments came after a Philippine security official said Wednesday that the country had deployed a fresh batch of marines and supplies to Ren'ai Reef.

The spokeswoman urged the Philippines to cease all provocative acts and work together with China to safeguard peace and stability in the South China Sea.