[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/images/09/18/art.hclinton.0918.gi.jpg caption="Secretary of State Hillary Clinton outlines sweeping agenda for U.N. conference."]
WASHINGTON (CNN) - Secretary of State Hillary Clinton laid out an ambitious U.S. agenda Friday for next week's United Nations gathering, citing issues such as nuclear non-proliferation, climate change, women's rights and ongoing wars.
She also strongly defended the Obama administration's decision to scrap Bush-era plans for a missile defense shield in Europe, calling it a decision that will ultimately leave the United States and its allies better positioned to defend against a potential threat from Iran.
"Our agenda is ambitious," she told an audience at the Brookings Institute when discussing the highly anticipated U.N. session. It stems from
President Barack Obama's belief that the United Nations is "a critical, central institution."
Obama is slated to makes his first appearance before the U.N. General Assembly next week. He is scheduled to address a meeting on climate control on Tuesday, address the General Assembly on Wednesday, and chair a special session of the U.N. Security Council dealing with nuclear non-proliferation on Thursday.
Obama's U.N. engagement marks a sharp shift in emphasis from George W. Bush's administration, which generally placed a lower priority on the need to act through international institutions.
Emphasizing the issue of non-proliferation, Clinton said that Iran's failure to prove that its nuclear program will not be used for military
purposes remains a source of "deep concern" to the international community. She promised continuing "costs" for Iran in the form of diplomatic isolation and economic sanctions if Tehran does not allow greater international oversight of the program.
Clinton defended the administration's decision to open the door to talks with the Iranian government, which has been criticized for cracking down on domestic political opponents in the wake of its disputed June presidential election.
"Dialogue along doesn't guarantee any outcome," she conceded. But she added that Bush's refusal to engage with Tehran didn't yield any progress on the nuclear issue or reduce Iranian support for terrorist groups.
At the same time, she warned, the Obama administration is not seeking greater diplomatic engagement "just for the sake of talking." She stressed that U.S. officials are hoping for "some movement" on Iran's part by the end of the year.
Clinton defended the U.S. troop drawdown in neighboring Iraq, noting that the relationship between Washington and Baghdad is entering what she termed a "period of transition."
A "new, sustained and more mature partnership" is coming, she said, one in which a stable, sovereign Iraq can contribute to peace in the Middle East.
Turning to central Asia, the secretary emphasized the continuing need to roll back al Qaeda and other extremists in Afghanistan and Pakistan.
Afghanistan's recent election - with its charges of corruption and a disputed outcome - illustrates both the possibilities and challenges in the embattled Islamic republic, she said.
"Corruption is as big a national security threat as I can imagine," she said. The United States has "to take some of the responsibility" for it in
Afghanistan. "We aided and abetted it in implicit ways by not demanding more earlier."
Regarding the quest for a comprehensive Middle East peace, Clinton said it is fitting that next week's U.N. gathering is happening at the end of the Muslim holy month of Ramadan and amid the Jewish high holidays of Rosh Hashanah and Yom Kippur.
The administration is "very patient and very determined" to bring Palestinians and Israelis to the bargaining table, she said. But ultimately,
she noted, the decision to reach an agreement is not in U.S. hands.
Clinton opened her remarks by raising the administration's controversial decision on missile defense.
Obama is not "shelving" missile defense plans, she argued. The Pentagon will instead deploy a more comprehensive, proven system on a faster timetable than had been proposed under Bush, she asserted.
"We would never, never walk away from our allies," she said. "We believe this is a decision that will leave America stronger" and more capable of defending against the threat posed by missiles launched by Tehran.
Clinton denied critics' claims that pressure from Russia - which had opposed the previous system - was a factor in the decision.