The Chinese mainland warned Japan on Thursday it was putting relations at risk by allowing former Taiwan "president" Lee Teng-hui to visit, as Lee courted more controversy by suggesting he might go to a Tokyo war shrine.

Lee could earn yet more wrath if he goes to the Yasukuni Shrine, which many in Asia see as a symbol of Japan's wartime militarism.

Although Japan says Lee's 11-day stay is for tourism only, Beijing suggested that the trip would hurt ties already strained by issues stemming from Japan's World War Two aggression and disputes over borders and energy resources.

"The aim of Lee Teng-hui's visit to Japan is to push forward Taiwan independence and to undermine Sino-Japan relations," Chinese Foreign Ministry spokeswoman Jiang Yu told a regular news conference.

"We feel strongly dissatisfied with Japan for allowing Lee to visit the country."

Yasukuni honours millions of Japanese war dead -- among them soldiers from Taiwan and Korea who fought for their colonial ruler at the time -- but also a handful of convicted war criminals, including wartime prime minister Hideki Tojo.  

The turning point of the frayed Sino-Japanese ties was the departure last year of prime minister Junichiro Koizumi, whose regular visits to Yasukuni brought routine condemnation from Beijing. His replacement, Shinzo Abe, has so far avoided going to the shrine.

But Jiang hinted on Thursday that Japan was not doing its part to keep relations on an even keel.

"It takes the efforts of both sides to maintain the stable development of relations between The Chinese mainland and Japan," she said.

"We hope Japan can attach importance to the mainland's serious concern, and properly resolve the issues of history and Taiwan through actions," she said.