Dozens of Japanese politicians are expected to visit a controversial war shrine Thursday, in a move sure to anger China and South Korea which see it as a potent symbol of Tokyo's imperialist past.

The annual visit to Yasukuni shrine, marking the anniversary of Japan's surrender in World War II, is a regular sore point for Tokyo's neighbours but the latest trip comes with relations plumbing new depths as territorial fights exacerbate tensions.

Japanese Prime Minister Shinzo Abe, a hawkish nationalist who has defended lawmakers' earlier visits to the leafy shrine in the heart of Tokyo, will not attend the event, AFP sources and local media have said.

Key ministers including Abe's deputy Taro Aso and Foreign Minister Fumio Kishida are reportedly staying away as well.

But Abe may give a ritual offering as he did earlier this year when nearly 170 lawmakers visited the shrine for a spring festival, grabbing international headlines and sparking diplomatic protests.

The shrine honours some 2.5 million citizens who died in World War II and other conflicts, including 14 war criminals such as General Hideki Tojo, who authorised the attack on Pearl Harbour which drew the US into the war.

Visits to Yasukuni by Japanese lawmakers enrage neighbouring nations which view them as an insult and painful reminder of Tokyo's imperialist aggression in the first half of the 20th century, including a brutal 35-year occupation of the Korean peninsula.

On last year's surrender anniversary, more than two dozen lawmakers made their annual pilgrimage to the site near Japan's Imperial Palace, drawing immediate protests from Seoul and Beijing.

On Tuesday, Seoul lashed out ahead of this week's expected visit, saying "our government and people will never tolerate such visits".

"We once again stress that there should be no trips by top Japanese politicians to the Yasukuni shrine," South Korean foreign ministry spokesman Cho Tai-Young told reporters.

Chinese state media on Wednesday immediately reported the Japanese premier's decision not to visit the "notorious" shrine.

Earlier in the week, the 35th anniversary of Japan and China normalising diplomatic relations quietly passed with almost no fanfare as relations remain frozen following maritime skirmishes over a set of East China Sea islands at the heart of a sovereignty dispute.

Observers have warned that the contested islands, which are believed to harbour vast mineral resources beneath their seabed, could be the flashpoint for military conflict between the two Asian giants.

Japan's premier has mostly focused his attention on stoking the country's economy since sweeping December elections, but he also openly mulled changing the pacificist constitution imposed on Japan by the US and it allies after the war.

The move would be aimed at turning the country's defence forces into a regular military, a possibility that has jangled nerves among Japan's neighbours.