Japan on Thursday appointed a new ambassador to China, months after the last nominee died before he could take up his post and as tensions simmer between Tokyo and Beijing over disputed territory.

Career diplomat Masato Kitera's appointment will be effective on Monday, the foreign ministry said, while local media reported that the 60-year-old will be dispatched to Beijing next month to formally succeed Uichiro Niwa.

Japan initially picked Shinichi Nishimiya, another career diplomat, for the post but before he could take up the role he fell ill in a Tokyo street in September and was taken to hospital, dying a few days later.

Kitera is set to become Tokyo's point man in the ongoing dispute over an island chain in the East China Sea, which Tokyo controls under the name the Senkaku Islands but Beijing claims as the Diaoyu Islands.

Their nationalisation in September provoked sometimes violent anti-Japanese demonstrations across China that targeted Japanese businesses.

A subsequent consumer boycott of Japanese produce has dented the huge trade ties between the two countries, notably in the automobile and home electronics sectors.

Niwa raised hackles at home when he accurately predicted a plan by Tokyo's nationalist governor to buy the islands could cause a crisis between China and Japan, jeopardising economic ties.

Kitera joined the ministry in 1976 and is currently serving as assistant chief cabinet secretary in the prime minister's office.