UN Security Council Passes Resolution Promoting Nuclear Disarmament

In one of his many firsts on the international stage, President Obama chaired a meeting of the U.N. Security Council today where a resolution reaffirming the U.N.'s goal of a world without nuclear weapons passed unanimously.

Obama, who delivered an unusually blunt speech to the United Nations General Assembly Wednesday, became the first ever U.S. president to chair this meeting.

Video of President Obama pushing his goal of a nuke free world during a UN Security Council meeting.Play

"We now face proliferation of a scope and complexity that demands new strategies and new approaches," the president said. "The historic resolution we just adopted enshrines our shared commitment to a goal of a world without nuclear weapons, and it brings Security Council agreement on a broad framework for action to reduce nuclear dangers as we work toward that goal."

The resolution calls for further progress on nuclear arms reductions through a strengthened Nuclear Non-proliferation Treaty, a U.N. treaty first opened for signature in 1968, and since amended, under which nuclear power nations agree to refrain from transferring nuclear weapons or related technology to any non-nuclear weapon state and to "pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a treaty on general and complete disarmament under strict and effective international control." A total of 187 nations have signed the treaty, though Israel, India, and Pakistan are not among them, and North Korea withdrew from the treaty in 2003.

VIDEO: Presidents Obama and Medvedev suggest sanctions against Iran.Play

Today's resolution calls for improved security for nuclear weapons materials, and calls for the convening of a Nuclear Security Summit in 2010 and proposes ways to deter any nation from withdrawing from the Nuclear Non-proliferation Treaty. It does not mention Iran or North Korea by name, but White House officials say it reaffirms previous resolutions against them.

The president was accompanied by Secretary of State Hillary Clinton, U.S. Ambassador to the U.N. Susan Rice and White House Chief of Staff Rahm Emanuel.

Former American diplomats Henry Kissinger, George Shultz, Sam Nunn and Bill Perry, who were present at the session, called it an important step.

"The Summit in the UN Security Council brings much-needed global focus to the risks posed by the spread of nuclear weapons, nuclear know-how and nuclear material. By convening heads of state, the meeting can help build the necessary political will around the urgent steps required to reduce nuclear dangers," they said in a statement.

Obama seemed to have a celebrity status at the meeting. There are more delegates snapping photos of the president as he worked his way around the room than press photographers.

Gaining Global Support

After rebuking Iran and North Korea Wednesday for pursuing nuclear arms, Obama again pushed world powers to commit to reducing their nuclear stockpiles and urged developing nations not to pursue nuclear weapons.

This renewed push comes after Obama convinced Russian President Dmitry Medvedev to say sanctions against Iran may be inevitable.

"Our task is to create such a system of incentives that would allow Iran to resolve its fissile nuclear program but at the same time prevent it from obtaining nuclear weapons" the Russian president said after meeting with Obama Wednesday. "As to sanctions, Russia's belief is very simple, and I stated it recently. Sanctions rarely lead to productive results. But in some cases sanctions are inevitable."

Making progress toward getting Russia to more aggressively oppose Iran's nuclear program was likely not an easy task. Russia has long backed Iran and has been hesitant to get on board the sanctions the United States and some European countries favor.

"I think we also both agree that if Iran does not respond to serious negotiations and resolve this issue in a way that assures the international community that it's meeting its commitments and is not developing nuclear weapons, then we will have to take additional actions and that sanctions, serious additional sanctions, remain a possibility," Obama said.

Even though China signed on to the resolution, it's position remains slightly blurry. In Beijing today, an official told reporters the country didn't think further pressure on Iran or sanctions would be effective.

"We believe that sanctions and exerting pressure are not the way to solve problems and are not conducive for the current diplomatic efforts on the Iran nuclear issue," Foreign Ministry spokeswoman Jiang Yu said.

Obama Warns of Nuclear Weapons

Making disarmament the first point of his "four pillars," the president yesterday painted a grim picture of a world with nuclear weapons. He himself committed to the ratification of the nuclear test ban treaty and work with other countries to ban testing altogether.

"We must stop the spread of nuclear weapons and seek the goal of a world without them. This institution was founded at the dawn of the atomic age, in part, because man's capacity to kill had to be contained," he told delegates and world leaders. "For decades, we averted disaster even under the shadow of a superpower standoff. But today the threat of proliferation is growing in scope and complexity. If we fail to act, we will invite nuclear arms races in every region and the prospect of wars and acts of terror on a scale that we can hardly imagine."

Iranian President Mahmoud Ahmadinejad dismissed the threat his country may pose to the world, instead turning the tables on developed countries and the United States for being the one country that has actually deployed its nuclear bomb.

"The Islamic Republic of Iran is a member of the IAEA [International Atomic Energy Agency] and is committed to the NPT," the fiery leader told the U.N. General Assembly Wednesday evening. "All our nuclear activities are transparent, peaceful and under the watchful eyes of IAEA inspectors. Why then are there objections to our legally recognized rights? Which governments object to these rights? Governments that themselves benefit from nuclear energy and the fuel cycle. Some of them have abused nuclear technology for non-peaceful ends including the production of nuclear bombs, and some even have a bleak record of using them against humanity."

Barack Obama Heads to Pittsburgh for G-20

The president this afternoon will head to Pittsburgh for the Global Economic Summit with the G-20 industrialized countries, hoping to turn the attention to economy and global financial regulations.

The president spoke Wednesday about his vision for a global economy "that advances opportunity for all people." Today and Friday he is expected to push other countries to eliminate some subsidies for oil, gas and other fossil fuels.

"In Pittsburgh, we will work with the world's largest economies to chart a course for growth that is balanced and sustained," the president told the U.N. General Assembly. "That means vigilance to ensure that we do not let up until our people are back to work. That means taking steps to rekindle demand so that a global recovery can be sustained. And that means setting new rules of the road and strengthening regulation for all financial centers, so that we put an end to the greed and the excess and the abuse that led us into this disaster and prevent a crisis like this from ever happening again."

The idea of a global financial regulator has been met with mixed reviews, with some countries saying it won't work.

"We can't let the need for reform fade as the memory of the crisis recedes," Treasury Secretary Tim Geithner said before the House Financial Services Committee Wednesday. "Time is the enemy of reform. As some normalcy returns to our financial system and our economy, we cannot let it be cause for complacency. We must act to correct the regulatory problems that have left our financial system so fragile and prone to future trouble."

Analysts say all eyes will be on Obama to chart out a course on the economy.

"This will be the first time the ball is really in Obama's court," said Steven Schrage, a business analyst with the Center for Strategic and International Studies.

Security has been tightened in Pittsburgh ahead of the president's arrival, as fired up protestors take to the streets, demanding new jobs and more serious work to tackle climate change.

Some economists are skeptical that anything concrete will come out of the meetings.

"I think they are arriving in Pittsburgh with kind of a self-satisfied smugness," Global Economic Policy Strategist David Smick told ABC News. "It's a, you know, 'We've bought the world economy and financial system back from the brink,' but they haven't dealt with the fundamental problem that got us into this difficulty in the first place."

ABC News' Huma Khan contributed to this report.