Chinese President Xi Jinping did not support Japan's claim over the Russian-held islands off Hokkaido in his talks with Russian counterpart Vladimir Putin last month, according to a Chinese source familiar with the matter, ditching a long-held stance of recognizing them as Tokyo's.
Xi told Putin in their meetings in Moscow that China "does not take either side" regarding the territorial row, in a shift to neutrality from China's position indicated by then Chinese leader Mao Zedong in 1964 to view the four disputed islands as belonging to Japan, the source said.
Bilateral negotiations over the islands known as the Northern Territories in Japan and the Southern Kurils in Russia have been suspended since Tokyo imposed punitive sanctions against Moscow following its invasion of Ukraine.
The change in China's position could make it more difficult to settle the decades-long dispute as Moscow is unlikely to concede on the issue now with backing from Beijing, observers say.
In the March 20-21 talks, Putin stressed the importance of promoting a special duty-free zone set up on the contested islands last year and called for investment by Chinese companies, according to the source.
With an improvement of Tokyo-Seoul ties marked by summit talks between Japanese Prime Minister Fumio Kishida and South Korean President Yoon Suk Yeol on March 16, Putin said Russia cannot expect investment from South Korean firms, the source added.
In response, Xi conveyed to Putin China's neutral stance on the territorial row but declined to make it clear whether Beijing would let its businesses join the project, saying he will leave the matter to Zheng Shanjie, chairman of the National Development and Reform Commission, the source said.
Tokyo has expressed regret over the establishment of the special tax-free zone on the disputed islands in March last year.
In July 1964, Mao told a delegation of the Japan Socialist Party sent to China that he believes the Russian-held islands "should be returned to you," announcing Beijing's support for Tokyo's territorial claim.
The Chinese government had maintained this position, even though it did not publicly mention that stance in recent years. Maps in China show the disputed islands as "occupied by Russia."
Japan says the Soviet Union illegally seized the islands -- Etorofu, Kunashiri, Shikotan and the Habomai islet group -- soon after Japan's surrender in World War II on Aug. 15, 1945. Russia claims the action was legitimate.