In an unprecedented prerecorded video message aired Monday, Emperor Akihito expressed concern about how his advanced age is affecting the performance of his public duties. The speech was widely interpreted as conveying his wish to abdicate in the near future.

The 82-year-old Emperor carefully avoided discussing any specific ideas to revise the Imperial succession system, which does not allow an emperor to step down before he dies.

But he did point out that he has already had two operations and now has the keen feeling that his strength has decreased.

“I am already 80 years old, and fortunately I am now in good health. However, when I consider that my fitness level is gradually declining, I am worried that it may become difficult for me to carry out my duties as the symbol of the State with my whole being as I have done until now,” the Emperor said in the 10-minute speech, which was televised nationwide.

Although he believes visiting various places throughout the country and sharing joy and sorrow with the people is a very important duty, the Emperor said his advanced age will eventually make it difficult to fully do this.

“In coping with the aging of the Emperor, I think it is not possible to continue reducing perpetually the Emperor’s acts in matters of state and his duties as the symbol of the State,” he said.

The Constitution strictly prohibits an emperor from engaging in any political activities, and any revision to the Imperial system is considered politically sensitive. This is likely why the Emperor has avoided discussing any specific ideas to revise the succession system that is based on the Imperial House Law.

The Emperor went on to say: “Even under such circumstances, it is my hope that by thoroughly reflecting on our country’s long history of emperors, the Imperial family can continue to be with the people at all times and can work together with the people to build the future of our country, and that the duties of the Emperor as the symbol of the State can continue steadily without a break. With this earnest wish, I have decided to make my thoughts known.”

Prime Minister Shinzo Abe spoke with reporters shortly after the video was aired.

“I would like to take seriously the fact that the Emperor addressed the nation,” Abe said. “Given the age of the Emperor and the burden of his duties, I believe we need to think what grievance it causes him and what we can do.”

For an emperor to abdicate, the Imperial House Law would probably need to be revised, but any talk of changing the Imperial system would likely spark controversy.

According to a nationwide telephone survey by Kyodo News this month, 85.7 percent of the 1,008 respondents said abdication should be legalized as an option for the emperor and his successors by revising the Imperial House Law.

But many right-leaning nationalist politicians and intellectuals oppose any revision to the law, saying that allowing an emperor to step down based on his own will could damage the stability of the Imperial system in the long run.

“The Imperial House Law is a permanent law. If any articles about abdication are inserted, it could bring confusion to the succession system and the status of the Imperial family,” argued Hidetsugu Yagi, a professor of law at Reitoku University, in an article published in Seiron, a right-wing monthly magazine.

Yagi and other intellectuals have argued that invoking Article 16 of the Imperial House Law would be enough to resolve the Emperor’s concerns.

Article 16 allows someone in the Imperial family to serve as a regent to take over the emperor’s duties if he is a minor or has suffered from severe disease or accident.

But in the video message, the Emperor appeared to have a negative view of this proposal.

“Even in such cases, however, it does not change the fact that the emperor continues to be the emperor till the end of his life, even though he is unable to fully carry out his duties as the emperor,” he said.

The Emperor also pointed out that if an emperor’s health deteriorates and becomes severe, it would adversely affect the nation.

He didn’t elaborate on this, but shortly before and after his father, Emperor Hirohito, posthumously known as Emperor Showa, became ill and died in January 1989, festive events were canceled nationwide and the news coverage dominated the media for months.

The government is now expected to set up a panel of experts and intellectuals familiar with the Imperial system to debate the matter. The Diet would then need to reach a consensus and draft legislation to revise the Imperial House Law, based on the panel’s proposals. The whole process, even if successful, could take a few years, observers say.

Under the Constitution and the Imperial House Law, the system of Imperial succession gives no consideration to the will of an emperor. This means an emperor is obliged to serve until death, after which the crown prince is bound to automatically succeed him.

During an Upper House session in 1984, Satoru Yamamoto, then a senior official at the Imperial Household Agency, told lawmakers that the Imperial House Law does not allow an emperor to abdicate because it is designed “to stabilize the status of the emperor.”

“That’s the reason why the law doesn’t allow an emperor to abdicate,” Yamamoto said.

Indeed, talk of revising the Imperial system has always caused controversy.

In 2005, Prime Minister Junichiro Koizumi set up a panel of intellectuals that eventually submitted a report recommending the Imperial House Law be revised to allow the eldest child of an emperor — regardless of gender — to be the first in line to the throne.

According to the Imperial House Law, only a man of the male succession line is allowed to ascend the Chrysanthemum Throne. At the time, the sustainability of the emperor system was being threatened by the Imperial family’s low number of young male heirs.

According to opinion polls, 70 to 80 percent of the nation supported the panel’s conclusion. But right-leaning conservative politicians and scholars strongly opposed it, arguing it would destroy the long-held tradition of the male-only succession system.

Abe, who was then chief Cabinet secretary, was believed to be among the opponents.

Koizumi ended up scrapping the proposal after a boy was born to Prince Akishino in September 2006.

Koichi Yokota, a professor emeritus of constitutional studies at Kyushu University, said the Emperor now appears to be leading public discussion on the abdication issue.

This is not desirable given his political neutrality strictly required by the Constitution, Yokota said.

“What the Emperor said in the video is just his private view. It is politicians who should lead such discussions,” he said.

Yokota also said the Emperor is now engaging in too many public activities, although the Constitution only stipulates that emperors shall perform “acts in matters of state.” Reducing nonessential work should be an option, he said.

Yokota also pointed out that the Imperial system is now facing many other critical issues, such as whether a woman of the female-succession line should be allowed to become a reigning empress.

If the government sets up any panel of experts on abdication issues, it should address such issues as well, Yokota said.

Staff writer Tomohiro Osaki contributed to this report