The two leaders will meet in Takaichi's home region of Nara in western Japan, days after Lee visited Chinese leader Xi Jinping in Beijing.

Looming in the background is Japan's heated diplomatic spat with China, triggered by Takaichi's suggestion in November that Japan could intervene militarily if China attacks Taiwan.

China, which regards Taiwan as its own territory, reacted angrily, blocking exports to Japan of "dual-use" items with potential military applications, fuelling worries in Japan that Beijing could choke supplies of much-needed rare earths.

The two US allies are also expected to compare notes on Washington after President Donald Trump's unpredictable tariffs and "America First" approach, analysts said.

Tense regional geopolitics could provide Takaichi and Lee "further impetus for wanting to build stronger relations", said Benoit Hardy-Chartrand, an East Asian geopolitics expert at Temple University's Tokyo campus.

Lee and Takaichi, who both took office in 2025, last met in October on the sidelines of the APEC regional summit in Gyeongju in South Korea.

It will be Lee's second visit to Japan since August, when he met Takaichi's predecessor Shigeru Ishiba.

Lee and Takaichi will hold a summit meeting and have dinner on Tuesday to discuss regional and global issues.

In public, they are expected to stress warming ties, cooperation in various fields and their desire to continue their "shuttle diplomacy" of regular meetings.

"Behind closed doors, the leaders will certainly discuss the current Japan-China crisis, as Beijing's retaliatory measures, including export controls, will have an impact on Korea as well," Hardy-Chartrand told AFP, with the supply chains of the three nations deeply intertwined.

Lee said in an interview with Japanese public broadcaster NHK aired on Monday that it was not his place to "intervene or get involved" in the Japan-China row.

"From the standpoint of peace and stability in Northeast Asia, confrontation between China and Japan is undesirable," he said. "We can only wait for China and Japan to resolve matters amicably through dialogue."

- Bitter memories -

Hardy-Chartrand said he believed "the South Korean government felt that it was necessary for President Lee to visit Japan not too long after going to China, in order to demonstrate that Seoul is not favouring one side over the other".

Lee and Takaichi are also expected to discuss their relations with the United States because the unpredictable Trump "has put in doubt old certainties and highlighted the importance of strengthening their ties", he said.

Yee Kuang Heng, a professor in international security at the University of Tokyo, did not expect Lee to bring any particular message from Xi to Takaichi.

"However, the two leaders may discuss the fallout from China's economic coercion that both ROK (South Korea) and Japan have experienced over the years," Heng told AFP.

"Takaichi will be wary of China's wedge strategy designed to drive divisions between ROK and Japan and will want to re-emphasise common ground shared between Seoul and Tokyo."

On the bilateral front, bitter memories of Japan's brutal occupation of the Korean peninsula from 1910 to 1945 have cast a long shadow over Tokyo-Seoul ties.

Lee's conservative predecessor Yoon Suk Yeol, who declared martial law in December 2024 and was removed from office, had sought to improve relations with Japan.

Lee is also relatively more dovish towards North Korea than was Yoon, and has said that South Korea and Japan are like "neighbours sharing a front yard".