Prime Minister Junichiro Koizumi reiterated Thursday his determination to uphold the nation's antiwar pledge as he attended a memorial marking the 57th anniversary of Japan's surrender in World War II.

About 5,000 relatives of the war dead and 1,000 guests, including Emperor Akihito, Empress Michiko and leading figures from the public and private sectors, took part in the annual ceremony at Nippon Budokan Hall in Tokyo.

"This year marks the 50th year after the San Francisco Peace Treaty took effect and our country regained its sovereignty," Koizumi said.