MANILA: 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 began their first 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 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 Japan and allied US and Philippine forces leveled the capital city and left more than 100,000 dead, according to Philippine historians.

Relations between the Asian nations have improved dramatically in the seven decades since the war. Japan has become a major trading partner and aid donor to the Philippines, and the countries are bolstering defence ties in the face of China's military rise.

Akihito and Empress Michiko were met at Manila's airport by President Benigno Aquino III and his top Cabinet members.

Aquino will formally welcome Akihito at the presidential palace on Wednesday for talks. The president will hold a state banquet for Akihito and Michiko later Wednesday.

Defence Secretary Voltaire Gazmin, among the Philippine officials who welcomed Akihito at the airport, said the first visit by a Japanese emperor to the country following the last world war was a milestone.

The Filipino generation that saw the horrors of the Japanese occupation in the 1940s still remembers that period, but Gazmin said it is time to move on as the two nations, now strategic allies, face common security concerns in the region.

"It's really more painful for us because my father was a veteran soldier who was forced into the 'death march,'" Gazmin told The Associated Press, referring to the Bataan death march, when Japanese soldiers forced tens of thousands of Filipino and American troops to march 100 kilometres (65 miles) from the Bataan Peninsula to prison camps under intense heat and harsh treatment. Thousands died, but Gazmin's father survived.

"We should move forward and forget and work for a better relation," Gazmin said. "It's a necessity, we need allies for our current needs."

Akihito, 82, is to pay his respects at memorials for both Philippine and 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.

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