Detailing the Japanese response to a hypothetical Taiwan crisis, Takaichi appeared to dial back on her remarks in November that suggested Tokyo could intervene militarily during a potential attack on the island.

That comment provoked the ire of Beijing, which regards the democratic island as its own territory.

Asked during a news programme on Monday about those remarks, Takaichi pointed out that in the event of conflict, Japan and the United States might jointly conduct an evacuation operation to rescue Japanese and American nationals.

"If the US military, acting jointly with Japan, comes under attack and Japan does nothing and runs home, the Japan-US alliance will collapse," she said on the TV Asahi programme ahead of a snap election in February.

"If something serious happens there, we would have to go to rescue the Japanese and American citizens in Taiwan. In that situation, there may be cases where Japan and the US take joint action," the prime minister said.

She added: "We will respond strictly within the bounds of the law, making a comprehensive judgment based on the circumstances."

In the wake of Takaichi's comments in November, China has discouraged its nationals from travelling to Japan, citing deteriorating public security and criminal acts against Chinese nationals in the country.

Beijing is reportedly also choking off exports to Japan of rare-earth products crucial for making everything from electric cars to missiles.

On Tuesday, two popular pandas departed Tokyo for China, leaving Japan without any of the beloved bears for the first time in 50 years as ties between the Asian neighbours fray.