(CNN) Beloved Japanese Emperor Akihito has released his final annual birthday statement before he abdicates the throne in April -- the first Japanese monarch to do so in 200 years.

Sunday is his 85th birthday.

Noting the changes he experienced as Japan recovered from the war and was accepted back into the international community, Emperor Akihito said, "I have believed it is important not to forget that countless lives were lost in World War II and that the peace and prosperity of post-war Japan was built upon the numerous sacrifices and tireless efforts made by the Japanese people, and to pass on this history accurately to those born after the war. It gives me deep comfort that the Heisei Era is coming to an end, free of war in Japan."

"I hope that the Japanese people will be able to warmly welcome as members of our society those who come to Japan to work here," he said.

On the disasters, he said, "the catastrophic destruction caused by the force of nature was beyond my imagination."

Japan was crushed by a number of natural disasters this year, from a magnitude-6.7 earthquake to a deadly typhoon accompanied by flooding and heat waves. More than 120 people died from floods and landslides over the summer.

The disasters during his reign, Akihito said, have left an "indelible impression on my mind," referring to some of the greatest destructions Japan has seen, including the tsunami that hit Okushiri Island in 1993, the Great Hanshin-Awaji Earthquake in 1995 and the Great East Japan Earthquake in 2011.

Emperor Akihito and Empress Michiko

"I have been heartened to see that, in the face of such difficulties, the spirit of volunteering and other forms of cooperation is growing among the people and that the awareness of disaster preparedness and the capacity to respond to disasters are increasing," he said. "I am always touched by the sight of people coping in an orderly manner when disasters strike."

Known for his close relationship with his wife, who was the first commoner to marry into the royal family, the Emperor thanked the Empress for taking up the public role.

"As I come to the end of my journey as Emperor, I would like to thank from the bottom of my heart the many people who accepted and continued to support me as the symbol of the State. I am also truly grateful to the Empress, who herself was once one of the people, but who chose to walk this path with me, and over sixty long years continued to serve with great devotion both the Imperial Family and the people of Japan" Emperor Akihito said.