TAIPEI, Taiwan (AP) — Japan “crossed a red line” with comments by its new leader suggesting a potential military intervention over Taiwan, Chinese Foreign Minister Wang Yi said Sunday.

Remarks earlier this month by Japanese Prime Minister Sanae Takaichi that a Chinese naval blockade or other action against Taiwan could be grounds for a Japanese military response were “shocking,” Wang said in a statement posted on the Chinese Foreign Ministry’s website.

“It is shocking that Japan’s current leaders have publicly sent the wrong signal of attempting military intervention in the Taiwan issue, said things they shouldn’t have said, and crossed a red line that should not have been touched,” Wang said.

The most senior Chinese official to address the tensions so far, Wang added that China must “resolutely respond” to Japan's actions and that all countries have the responsibility to “prevent the resurgence of Japanese militarism.”

Takaichi’s remarks have led to rising tensions between the two countries over the past few weeks. Beijing on Friday sent a letter to U.N. Secretary-General Antonio Guterres criticizing Takaichi’s “grave violation of international law” and diplomatic norms.

“If Japan dares to attempt an armed intervention in the cross-Strait situation, it would be an act of aggression,” China's U.N. Ambassador Fu Cong wrote in the letter. “China will resolutely exercise its right of self-defense under the UN Charter and international law and firmly defend its sovereignty and territorial integrity.”

Beijing sees self-ruled Taiwan – a former Japanese colony – as its own territory, to be annexed by force if necessary. China objects to the involvement of other countries in Taiwan, notably the United States, which is the island’s main supplier of weapons, as well as U.S. allies in Asia, including Japan and the Philippines.

Takaichi's stance is seen as more forceful than that of previous Japanese prime ministers, who have expressed concern about China’s threat to Taiwan but haven’t publicly said how Japan would respond.

The prime minister later refused to retract her remarks but said she would avoid talking about specific scenarios in the future.