UNITED NATIONS — The new president of the U.N. General Assembly opened its 63rd annual session today by accusing some of the world body’s most powerful members for relying on warfare.

“It is a sad but undeniable fact that serious breaches of the peace and threats to international peace and security are being perpetrated by some members of the Security Council that seem unable to break what appears like an addiction to war,” Miguel d’Escoto Brockmann said, without specifying any countries.

During his acceptance speech in June, he criticized what he called “acts of aggression” in Iraq and Afghanistan without mentioning America by name.

Mr. d’Escoto, a Roman Catholic priest allied with Nicaragua’s leftist president, also took a swipe at America today for what he said was its “unjust” 46-year-long trade embargo against Cuba.

His remarks before a half-filled chamber were his first as president of the 192-nation assembly. He will preside over its yearlong session, including two weeks of ministerial meetings that begin next week.

Separately, Secretary-General Ban told The Associated Press in an interview that he would use the assembly’s ministerial session to hold talks with world leaders on issues ranging from climate change to the detention of the Burmese opposition leader, Aung San Suu Kyi.

He called it a top priority “to mobilize and galvanize all political wills and resources starting from now” to craft a new climate change agreement next year to succeed the 1997 Kyoto Protocol.

Speaking about Ms. Suu Kyi, Ban said Burma’s military junta “should release her from house arrest,” to allow the 63-year-old Nobel Peace Prize winner who has been on a recent hunger strike to lead “a genuine and free life.”

Much of Mr. d’Escoto’s antipathy was directed at the 15-nation Security Council, the United Nations’ most powerful body, which is dominated by the America, China, Russia, Britain, and France — the five permanent members with veto power.

That configuration reflects the balance of power at the end of World War II, when the U.N. was created. It was much on Mr. d’Escoto’s mind as he dedicated his presidency to seeking “the democratization of the United Nations” and to helping the “dispossessed.”

Turning to Cuba, Mr. d’Escoto wondered aloud why the United Nations has been powerless to overturn the American trade embargo imposed on Fidel Castro’s government in February 1962.

“If the opinion of more than 95 percent of the membership of the United Nations can be so casually ignored, of what use is this General Assembly?” he said.

The General Assembly’s resolutions aren’t binding, unlike the Security Council, which can set international law. But the assembly controls the U.N. budget and serves as a world forum for debate.

Mr. d’Escoto has long been a supporter of the Sandinista leader, Daniel Ortega, who once allied himself with Fidel Castro and the Soviet Union and won re-election as Nicaragua’s president in 2006. Mr. d’Escoto was foreign minister of Nicaragua when the Sandinistas ruled in the 1980s.

The assembly’s presidency rotates by region and lasts for a year. The assembly elected d’Escoto, who was born in Los Angeles, to succeed a Macedonian diplomat, Srgjan Kerim.

Mr. Kerim closed out his year as president with a news conference, where he praised the assembly’s last-minute consensus agreement last night to explore adding new members to the Security Council. Mr. Kerim used his prerogative to push through compromise language at the last minute.

“We have really accomplished something,” Mr. Kerim said. “The General Assembly is the only place for nations to talk on equal footing.”

The top candidates, if such a change were made, would likely include World War II-defeated nations Germany and Japan, along with developing powers India and Brazil. A U.N. working group began examining the possibility of expanding the council as long as 15 years ago.