"This is not the time to celebrate," Ms. Shourd, 32, said in prepared remarks for a New York news conference. "The only thing that enabled me to cross the gulf from prison to freedom alone was the knowledge that Shane and Josh wanted with all their hearts for my suffering to end."

Meanwhile, Iranian President Mahmoud Ahmadinejad arrived in New York to attend the U.N. General Assembly. He later met with U.N. Secretary-General Ban Ki-moon to discuss developments in Iraq, Afghanistan and the Middle East as well as efforts to resolve the dispute over Iran's nuclear program, the U.N. spokesperson's office said.

Mr. Ahmadinejad called Ms. Shourd's release "a huge humanitarian gesture" in an interview on "This Week With Christiane Amanpour." He called on the United States to release eight Iranians being detained after arrests he said were illegal.

Ms. Shourd thanked Iranians and Mr. Ahmadinejad in a carefully scripted return that spoke to the continuing delicacy of her situation. Iran has issued espionage-related indictments against her, Mr. Bauer and Mr. Fattal; the indictments could bring trials for the two men and proceedings in absentia for Ms. Shourd.

But she stressed their innocence in a case that has added to the roster of tensions between the United States and Iran.

The three were detained in July 2009 after Iranian officials said they intentionally crossed the country's border from Iraq. Echoing accounts their families have given in their absence, Ms. Shourd said Sunday that the three had been hiking in a popular tourist area — near a waterfall in Iraq's Kurdistan region — and had no idea the border was nearby.

"If we were indeed near the Iraq-Iran border, that border was entirely unmarked and indistinguishable," she said.

"Shane and Josh do not deserve to be in prison one day longer than I was," she said. "We committed no crime, and we are not spies. We in no way intended any harm to the Iranian government or its people and believe a huge misunderstanding led to our arrest and prolonged detention."

Ms. Shourd's mother has said Ms. Shourd has health problems, including a breast lump and precancerous cervical cells. Ms. Shourd said Sunday that doctors in Oman, where she went immediately after her release, determined she was physically well.

Officials in Oman — an ally of both Iran and the United States — mediated a $500,000 bail for Ms. ♠Shourd that satisfied Iranian authorities and apparently did not violate U.S. economic sanctions against Iran. The source of the bail payment has not been disclosed.

Ms. Shourd and Mr. Bauer lived together in Damascus, Syria, where Mr. Bauer was working as a freelance journalist and Ms. Shourd as an English teacher. Mr. Fattal, an environmental activist and a fellow graduate of the University of California at Berkeley, came to visit them last July, and the three went hiking.

"My hope is that by learning who we are and how we came to be in this diverse and fascinating region of the world directly from my lips, it will help clear up any doubts and end Shane and Josh's detention," Ms. Shourd said.

She added that she hoped their experience would provide "an opportunity for Americans and Iranians to realize that an improved relationship would be in the best interest of all people."

Mr. Ahmadinejad gave no specifics in his interview with Miss Amanpour about whether Mr. Bauer and Mr. Fattal might also be released, saying that "the cases have to be examined."

*Associated Press writer Jennifer Peltz contributed to this report.