U.S. President Barack Obama has called for a "new era of engagement," telling the United Nations that leaders should take on more responsibility on global challenges.
His remarks came during his debut speech to the UN's General Assembly.
In it, he sought to draw a contrast with the tone of the previous Bush administration and its uneasy relationship with the world body.
Obama said he had taken office at a time of widespread skepticism and distrust of his country.
"Part of this was due to opposition to specific policies, and a belief that on certain critical issues, America has acted unilaterally, without regard for the interests of others," Obama said.
He went on to list the multilateral credentials of his nearly nine-month-old administration.
'Global Response To Global Challenges'
America, Obama said, had worked with others to forge a coordinated international response to the economic crisis. It had joined the UN human rights council. It also had move "from a bystander to a leader" in tackling climate change.
But he said other countries could not expect America to solve the world's problems alone.
"Those who used to chastise America for acting alone in the world cannot now stand by and wait for America to solve the world's problems alone," Obama said. "We have sought -- in word and deed -- a new era of engagement with the world. Now is the time for all of us to take our share of responsibility for a global response to global challenges."
Among those challenges are halting the spread of nuclear weapons and seeking a world without them.
On that score, Obama had words for North Korea and Iran, which he said threatened to take the world down a "dangerous slope" with their nuclear programs.
He said the time had come to resume Israeli-Palestinian peace talks without preconditions. And he called for cooperative work on preserving the planet, saying our responsibility there "must not be deferred."
On the global economy, Obama said America would work with other major countries at this week's G-20 summit to chart a course for balanced and sustained growth and to agree tighter rules to put an end to the "greed, excess, and abuse" that led to the financial crisis.
So far, he said, the world had not lived up to its responsibilities. But he said the time had come for countries to stop focusing on what divides them and start focusing on what brings them together.
"We have reached a pivotal moment. The United States stands ready to begin a new chapter of international cooperation -- one that recognizes the rights and responsibilities of all nations," Obama said. "With confidence in our cause, and with a commitment to our values, we call on all nations to join us in building the future that our people so richly deserve."
Obama's speech was followed by another debut at the UN gathering -- by Libyan leader Moammar Qaddafi.
Qaddafi delivered an address that went well over an hour in which he accused veto-wielding members of the UN Security Council of betraying the organization's founding principles.
"Veto power should be annulled," Qaddafi said. "The Security Council did not provide us with security but with terror and sanctions."
He also proposed moving the UN headquarters from New York.
-- compiled from RFE/RL and additional wire reports