Emperor Akihito turned 82 on Wednesday, paying tribute to all who suffered during World War II, including those in Japan and overseas who live with its legacy today. He said it is “most important” for Japan’s future that the war is remembered and understood.

“Looking back over the past year, I feel that it was a year in which I spent much time thinking about the war in various ways,” he said.

“With each passing year, we will have more and more Japanese who have never experienced war, but I believe having thorough knowledge about the last war and deepening our thoughts about the war is most important for the future of Japan,” he said.

The Emperor made the comments at a press conference held in advance of his birthday. Their publication was embargoed until the day itself.

The Emperor told reporters he is “beginning to feel” his age. “There were times when I made some mistakes at events,” he said, adding that he will try “to minimize such incidents by continuing to do the best I can” during official duties.

The news conference was barely that: In consideration of his age, only one question was allowed to be put to the Emperor. Last year, the press corps was allowed to throw two.

The Emperor and Empress Michiko, 81, spent parts of the year commemorating the war dead, visiting World War II battle sites and meeting with people who experienced the conflict both at home and abroad. In April, the Imperial Couple visited the Pacific island nation of Palau, the site of a major battle during the war.

“It pains me deeply to think of the many who lost their lives” during the war, the Emperor said, as they “could have led meaningful lives in various areas of society” had peace prevailed.

Recalling his trip to Palau, the Emperor said the country, when seen from the air, “is made up of beautiful islands surrounded by coral reefs,” but countless unexploded bombs remain submerged in the sea. He said, let it never be forgotten that the war “has imposed a heavy burden on the people living on those islands.”

His voice trembled as he spoke of the sinkings of many civilian vessels transporting military supplies and personnel, noting that the war took away many lives, including those of civilians such as the sailors who crewed the ships.

“In those days, Japan lacked command of the air and no battleships were available to escort the transport vessels. It gives me great pain to think of the feelings of the sailors who had to engage in transport operations under such conditions,” he said.

The Emperor also expressed sympathy for those affected by natural disasters this year, such as a volcanic eruption on Kuchinoerabu Island in Kagoshima Prefecture and heavy rain that pounded the Japanese archipelago in September. He praised the efforts of volunteers to help the victims.

Looking back on the year, the Emperor expressed the pleasure he took from two Japanese scientists winning Nobel Prizes in medicine and physics, and the successful test flight of the Mitsubishi Regional Jet, Japan’s first domestically produced commercial passenger jet.

U.S. Secretary of State John Kerry paid tribute to the state of bilateral relations that continue to prosper under Emperor Akihito.

“On behalf of President Obama and the people of the United States, I would like to take the opportunity to send my warmest wishes to the Emperor of Japan on the occasion of his birthday, and to congratulate the people of Japan on this national day of celebration,” Kerry said in a statement.

He said Washington and Tokyo share a “mutual commitment” to peace and prosperity for the Asia-Pacific region and beyond, and noted that the two nations are working as partners on matters of global concern, such as the fight against Ebola.