HONG KONG — The deterioration of China-Japan relations during the five years of Junichiro Koizumi's premiership has been reversed, but concrete progress needs to be made if the dramatic improvement in relations in the last 14 months is to be sustainable.

Already, both sides have made serious efforts to improve relations, beginning with the visit by Prime Minister Shinzo Abe to Beijing in October 2006, followed by the visit by Premier Wen Jiabao to Japan last spring.

Also being planned is an exchange of visits by Prime Minister Yasuo Fukuda and Chinese President Hu Jintao, most likely in the early part of next year. Those visits would take place on the 30th anniversary of the signing of a peace and friendship treaty by the two countries.