BEIJING, April 1 (Xinhua) -- China firmly opposes any actions by the Philippines that undermine China's sovereignty, rights and interests, and will take necessary measures to resolutely safeguard its territorial sovereignty and maritime rights and interests in the South China Sea, foreign ministry spokesperson Mao Ning said on Wednesday.

Mao made the remarks at a regular press briefing in response to the Philippines' illegal re-naming of China's Nansha Qundao.

China has indisputable sovereignty over the Nansha Qundao and its adjacent waters, Mao stressed.

She said that the Philippines has illegally delineated the so-called "Kalayaan Island Group" beyond its own territorial scope and assigned names to Chinese islands and reefs in the Nansha Qundao, adding that such acts violate China's territorial sovereignty and are inconsistent with the purposes and principles of the UN Charter and relevant international laws.