The spat between China and Japan was ignited by Prime Minister Sanae Takaichi's suggestion that Tokyo could intervene militarily in any attack on Taiwan.

China, which claims Taiwan as part of its territory and has not ruled out using force to take the democratic island, reacted furiously to Takaichi's comments.

Asked about the warning to Japanese visitors, foreign ministry spokeswoman Mao Ning said the "Chinese government has always and will continue to protect the safety of foreign citizens in China in accordance with the law".

The comments came as Masaaki Kanai, the top official in Japan's foreign ministry for Asia-Pacific affairs, held talks in Beijing with his Chinese counterpart Liu Jinsong over Takaichi's comments.

Mao said Beijing had reiterated a "strong protest" with Tokyo in the discussions.

"During the consultations, China once again lodged a strong protest with Japan regarding Japanese Prime Minister Sanae Takaichi's erroneous remarks concerning China," Mao said.

"Takaichi's fallacies seriously violate international law and the basic norms governing international relations", Mao said, adding her comments "fundamentally damage the political foundation of China-Japan relations".

AFP journalists saw Kanai leave Beijing's Ministry of Foreign Affairs after the talks with Liu shortly before 2:00 pm (0600 GMT) on Tuesday.