New York ? Making a plea for human rights, Pope Benedict XVI warned diplomats at the United Nations on Friday that international cooperation needed to solve urgent problems is “in crisis” because decisions rest in the hands of a few powerful nations.

The U.N. speech highlighted another active day on Benedict’s first papal trip to the United States, one that also included the first visit by the leader of the Roman Catholic Church to an American synagogue.

In his U.N. address, Benedict said that respect for human rights, not violence, was the key to solving many of the world’s problems.

While he didn’t identify the countries that have a stranglehold on global power, the German pope – just the third pontiff to address the U.N. General Assembly – addressed long-standing Vatican concerns about the struggle to achieve world peace and the development of the poorest regions.

On the one hand, he said, collective action by the international community is needed to solve the planet’s greatest challenges.

On the other, “we experience the obvious paradox of a multilateral consensus that continues to be in crisis because it is still subordinated to the decisions of a few.”

The pope made no mention of the United States in his speech, though the Vatican did not support the U.S.-led invasion of Iraq in 2003, which occurred despite the Bush administration’s failure to gain Security Council approval for it. At other moments on his trip, Benedict has been overtly critical of the U.S., noting how opportunity and hope have not always been available to minorities.

The pope said questions of security, development and protection of the environment require international leaders to work together in good faith, particularly when dealing with Africa and other underdeveloped areas vulnerable to “the negative effects of globalization.”

Benedict also insisted that the way to peace was by insuring respect for the dignity of human beings.

“The promotion of human rights remains the most effective strategy for eliminating inequalities between countries and social groups, and increasing security,” the pope said.

Those whose rights are trampled, he said, “become easy prey to the call to violence and they then become violators of peace.”

By contrast, the pope said, recognition of human rights favors “conversion of heart, which then leads to a commitment to resist violence, terrorism and war.”

While Benedict, a former university professor and theologian, has spoken out less on global conflicts than his predecessor, John Paul II, he too lived through the Second World War. He was drafted into the German army at war’s end and later deserted.

After three days in Washington, the pope took an early morning flight from the nation’s capital to New York City.

As it was in Washington, the pope was surrounded by well-wishers all day.