Secretary-General Ban Ki-moon warned Tuesday that the global financial crisis endangers the U.N. campaign to fight poverty, as he joined a host of world leaders calling for global leadership to restore order to international financial markets.

Addressing more than 120 world leaders and dozens of government ministers at the opening of the annual ministerial meeting of the U.N. General Assembly, Ban painted a grim picture of a world facing not only a financial crisis but food and energy crises as well as new outbreaks of war and violence and "new rhetoric of confrontation."

"We must do more to help our fellow human beings weather the gathering storm," he said. "I see a danger of nations looking more inward, rather than toward a shared future. I see a danger of retreating from the progress we have made, particularly in the realm of development and more equitably sharing the fruits of global growth."

Ban said he worried that nations are losing sight of the "new reality" -- that there are "new centers of power and leadership in Asia, Latin America and across the newly developed world" -- and that "in this new world, our challenges are increasingly those of collaboration rather than confrontation."

Ban's focus on global financial challenges and new cooperation come in a General Assembly session confronting a host of challenges, including Western pressure on Iran for its nuclear program and continued threats of terrorism, issues which U.S. President George W. Bush addressed in his speech before the gathered leaders shortly after Ban spoke.

Bush said he realizes that other nations are watching how the U.S. deals with the financial crisis, and said he is confident that the U.S. will act "in the urgent timeframe required" to prevent broader problems. He said his administration is with the U.S. Congress to come to fast agreement on a $700 billion bailout bill, in addition to other recent actions he called "bold steps" aimed at stabilizing markets and keeping credit flowing.

He did not ask for any action by other countries.

But speaker after speaker at Tuesday's assembly session made clear that the solution to the U.S. financial meltdown must be global.

France's President Nicolas Sarkozy called for a wholesale reform of the global financial system, urging major economic powers to meet before the end of the year to examine the lessons of the crisis.

"Let us rebuild capitalism in which credit agencies are controlled and punished when necessary, where transparency ... replaces opaqueness," Sarkozy said. "We can do this on one condition, that we all work together in our globalized world."

Brazil's President Luiz Inacio Lula da Silva also called for a global solution to the financial crisis and lashed out at speculators who he blamed for the "anguish of entire peoples."

"The global nature of this crisis means that the solutions we adopt must also be global and decided upon within legitimate, trusted multilateral fora, with no impositions," Silva said.

In his eighth and final speech to the General Assembly -- and after seven years of criticizing the U.N. for its huge, costly bureaucracy and indecisiveness in the face of grave problems -- Bush stressed that multinational organizations are now "needed more than ever" to combat terrorists and extremists who are threatening world order.

Bush said the international community must stand firm against the nuclear ambitions of North Korea and Iran. He scolded Russia for invading neighboring Georgia. And he said that despite past disagreements over the U.S.-led war in Iraq, members of the U.N. must unite to help the struggling democracy succeed.

"A few nations, regimes like Syria and Iran, continue to sponsor terror," Bush said. "Yet their numbers are growing fewer, and they're growing more isolated from the world. As the 21st century unfolds, some may be tempted to assume that the threat has receded. This would be comforting. It would be wrong. The terrorists believe time is on their side, so they've made waiting out civilized nations part of their strategy. We must not allow them to succeed."

Bush also urged the United Nations and other multilateral organizations to focus less on bureaucracy and more on results.

Earlier, Iran's president Mahmoud Ahmadinejad, in a series of interviews, blamed U.S. military interventions around the world in part for the collapse of global financial markets, and he said the campaign against his country's nuclear program was solely due to the Bush administration "and a couple of their European friends."

"Problems do not arise suddenly," Ahmadinejad said in an interview with the Los Angeles Times. "The U.S. government has made a series of mistakes in the past few decades. The imposition on the U.S. economy of the years of heavy military engagement and involvement around the world . . . the war in Iraq, for example. These are heavy costs imposed on the U.S. economy.

"The world economy can no longer tolerate the budgetary deficit and the financial pressures occurring from markets here in the United States, and by the U.S. government," he added.

The interviews came after the head of the International Atomic Energy Agency warned that he could not determine whether Iran is hiding some nuclear activities.

In a separate interview with National Public Radio, Ahmadinejad said he does not want confrontation with the United States. He said he wants diplomatic relations to develop between the two countries and was willing, for example, to cooperate on upholding security in Iraq.

"We do not have confrontations with anyone," he said. "The U.S. administration interferes, and we defend ourselves."

According to a report on Tuesday on the Web site of Iran's National Public Radio, Ahmadinejad claims that the "people of the world -- the majority actually -- support our stand."

Ban focused much of his speech on economic challenges and the U.S. financial meltdown which has spread around the world, saying "the global financial crisis endangers all our work -- financing for development, social spending in rich nations and poor, the Millennium Development Goals" to improve life for the poorest.

"If ever there were a call to collective action -- a call for global leadership -- it is now," Ban said.

"We need to restore order to the international financial markets," he said. "We need a new understanding on business ethics and governance, with more compassion and less uncritical faith in the `magic' of markets. And we must think about how the world economic system should evolve to more fully reflect changing realities of our time."

He urged world leaders to adopt a new trade deal to help developing countries at the Doha review conference later this year.

Last year -- and again this year -- thousands rallied at the United Nations to protest Ahmadinejad's speech. When Ahmadinejad was ushered to the podium of the General Assembly to speak last year, the U.S. delegation walked out, leaving only a low-ranking note-taker to listen to his speech.

Despite U.N. sanctions against Iran over its nuclear program, Ahmadinejad claimed vast international support for his position and said the campaign consisted "of only three or four countries, led by the United States and with a couple of their European friends."

The Iranian leader warned over the weekend that the military would strike back against anyone targeting his country's nuclear facilities.

"If anyone allows himself to commit even a tiny offense against Iran's legitimate interests, borders and sacred land, our armed forces will break his hand before he pulls the trigger," Ahmadinejad said during a military parade Sunday.

Iran insists its nuclear activities are geared only toward generating power. But Israel says the Islamic Republic could have enough nuclear material to make its first bomb within a year. The U.S. estimates Tehran is at least two years away from that stage.

Bush also is to meet Tuesday with Pakistani President Asif Ali Zardari. Topping their talks will be the series of suspected U.S. missile attacks and an American-led cross-border ground assault in Pakistan's volatile northwest that have angered public opinion.

The vice president of Sudan and leaders from Georgia, Lebanon, Kenya, Somalia, France, Liberia and Argentina are also among those addressing the General Assembly on Tuesday.