Countries that act unilaterally on the world stage undermine the authority of the United Nations and weaken the broad consensus needed to confront global problems, Pope Benedict said today.

In a major speech to the U.N. General Assembly, the Pope also said the international community sometimes had the duty to intervene when a country could not protect its own people from "grave and sustained violations of human rights."

The Pope, who arrived from Washington on the second leg of a six-day U.S. trip, was only the third pontiff in history to address the General Assembly.

Speaking in French and English from the Assembly's green marble podium, he gave a wide-ranging address on issues such as globalization, human rights and the environment.

The international community must be "capable of responding to the demands of the human family through binding international rules," said the 81-year-old Pope, who spoke after meeting privately with U.N. Secretary-General Ban Ki-moon.

He said the notion of multilateral consensus was "in crisis because it is still subordinated to the decisions of a few, whereas the world's problems call for interventions in the form of collective action by the international community."

While Benedict did not mention any country, this appeared to refer to the United States, which led the 2003 invasion of Iraq despite a Security Council refusal to approve it. The Vatican strongly opposed the recourse to war.

Benedict, who met U.S. President George W. Bush during his Washington visit, called for "a deeper search for ways of pre-empting and managing conflicts by exploring every possible diplomatic avenue, and giving attention and encouragement to even the faintest sign of dialogue or desire for reconciliation."

In an apparent reference to the conflict in the Sudanese region of Darfur, the Pope said every state had the "primary duty" to protect its citizens from human rights violations and humanitarian crises but outside intervention was sometimes justified.

"If states are unable to guarantee such protection, the international community must intervene with the juridical means provided in the United Nations Charter and in other international instruments," he said. The Pope called human rights, particularly religious freedom, "the common language and ethical substratum of international relations," and added that promoting human rights was the best strategy to eliminate inequalities.

"Indeed, the victims of hardship and despair, whose human dignity is violated with impunity, become easy prey to the call to violence, and they can then become violators of peace," he said in an apparent reference to social causes of terrorism.

Benedict called for religious freedom to be protected against secularist views and against majority religions that sideline other faiths -- an apparent reference to Muslim states where some Christian minorities report discrimination.

"It should never be necessary to deny God in order to enjoy one's rights," he said.

Diplomats from some 200 states gave him a standing ovation when he ended his speech by reading the phrase "peace and prosperity" in the six official languages of the United Nations -- English, French, Spanish, Arabic, Chinese and Russian.

Later, in the U.N. meditation room, he met U.N. staffers and wrote in the visitors' Golden Book a quote from the Prophet Isaiah: "Erit opus iustitiae pax" -- Latin for "Justice will bring about peace."

Later on Friday, the German-born Pope was due to visit a New York synagogue just before the start of the Jewish Passover holiday.

He will also visit a Manhattan parish founded by German immigrants in 1873.

The Pope arrived in Washington on Tuesday on his first visit to the United States as pontiff. On Thursday, he held a surprise meeting with victims of sexual abuse by priests in a bid to heal scars from a scandal that deeply tarnished the Catholic Church in the United States. Some three dozen protesters outside the U.N. headquarters held banners including one reading "Child sexual abuse is worse than terrorism."

One group wore T-shirts with the legend "Save 50 million children from sexual abuse by Catholic priests."