China has warned Japan's new government over its Taiwan policy, reiterating its opposition to including the island in the scope of the Japan-U.S. security alliance and urging Tokyo to act with caution over Taipei's invitation for former Prime Minister Junichiro Koizumi to pay a visit.

If the Japan-U.S. security alliance "exceeds the bilateral scope, it will trigger neighboring countries' worries and become a factor for instability and complexity in the regional security situation," Chinese Foreign Ministry spokesman Qin Gang said Thursday at a news conference.

"We firmly oppose including China and China's Taiwan in the scope of the Japan-U.S. security arrangement, either directly or indirectly, as it would constitute the infringement of China's sovereignty," Qin said, speaking after Prime Minister Shinzo Abe named his first Cabinet on Tuesday.

China regards Taiwan as a renegade province and says it would attack if the self-ruled island formally declares its independence and permanent separation from the mainland.