BEIJING - The entry of a Japan Self-Defense Forces vessel into the Taiwan Strait severely threatens China's sovereignty and security, and China firmly opposes it and has lodged strong protest with Japan, Chinese Foreign Ministry spokesman Guo Jiakun said on Friday.

Guo said at a regular press briefing that the Chinese military has handled the entry in accordance with laws and regulations.

Noting that Japanese Prime Minister Sanae Takaichi's erroneous remarks on Taiwan have already inflicted serious damage on China-Japan relations, Guo said Japan's dispatch of the Self-Defense Forces vessel into the Taiwan Strait to brandish its military might and engage in deliberate provocation is compounding the error.

"It once again exposes the dangerous attempt of certain individuals in Japan to militarily interfere in the Taiwan Strait and undermine peace and stability across the Strait," Guo said, adding that these moves also severely damage the political foundation of China-Japan relations.

The spokesman stressed that the Taiwan question bears on China's sovereignty and territorial integrity, as well as the political foundation of China-Japan relations, and it constitutes a red line that must not be crossed.

China once again urges the Japanese side to earnestly reflect on its mistakes, pull back from the brink, exercise prudence in its words and actions, and refrain from going further down the wrong path, Guo said.