TOKYO (AP) — Japan's emperor said Tuesday that his nation must remember the tremendous loss of life in the Philippines during World War II, as he and his wife embarked for a four-day visit to the Southeast Asian country.

"Many Filipinos, Americans and Japanese lost their lives in the Philippines during the war," Emperor Akihito said in a short statement he read before departing from Tokyo. "Especially in the battle in Manila, a tremendously large number of innocent Filipino civilians were victims. Upon making this visit, we need to bear this in mind at all times."

Japan occupied the Philippines during World War II. The 1945 battle for Manila between the Japanese and U.S. and Philippine forces leveled the capital city.

The 82-year-old Akihito will pay his respects at memorials for both the Philippine and the Japanese war dead.

He is the son of former Emperor Hirohito, under whose name Japan waged World War II. Akihito was 11 years old at the end of the war.

His role is symbolic and he holds no political power. He is relatively popular with the Japanese public. His wife, Empress Michiko, was the first commoner to marry into the Japanese royal family.

Japan-Philippines relations have improved dramatically in the seven decades since the war. Japan has become a major aid donor to the Philippines, and the countries are developing defense ties in the face of China's military rise.

The emperor's trip follows visits to the World War II battle sites of Palau last year and Saipan in 2005. He also prayed for Japanese and U.S. war-dead in Iwo Jima in 1994.