China has formally protested to Australia over an Australian military aircraft's deliberate intrusion into the airspace of China's Xisha Islands without permission, Foreign Ministry spokesman Guo Jiakun said on Thursday.

"China has taken measures to repel the intrusion with due professionalism and restraint," Guo told a daily news briefing, while rejecting the accusation that a Chinese fighter jet had endangered an Australian surveillance plane over the South China Sea.

Noting that the intrusion violated China's sovereignty and jeopardized national security, Guo urged Australia to cease such provocative actions.

"Australia should stop infringing on China's sovereignty and refrain from undermining peace and stability in the South China Sea," he said.