UNITED NATIONS -- President Barack Obama told the UN General Assembly Tuesday that signs of a diplomatic thaw between the United States and Iran are encouraging, but must be tempered by a decades-old mutual distrust and an American suspicion of Iran's nuclear program.
Obama said he was encouraged by statements from Supreme Leader Ayatollah Ali Khamenei and new President Hasan Rouhani rejecting nuclear weapons. To that end, Obama said he would direct Secretary of State John Kerry to negotiate with Iran.
Kerry and Iran Foreign Minister Mohammad Javad Zarif will meet Thursday in New York.
Obama's morning address served as a historic diplomatic volley toward his Iranian counterpart. Rouhani, who has made several conciliatory gestures in recent weeks, returned the favor in the late afternoon with his first-ever speech at the UN.
The new Iranian president expressed hope the two countries can constructively resolve their differences, but defended Iran's nuclear program. A much-discussed meeting between Obama and Rouhani never happened.
Obama made his way to the stage and while he struck a conciliatory tone toward Iran -- next to unheard of from a U.S. president in nearly four decades -- it was not without strong reservations.
"These statements made by our respective governments should offer the basis for a meaningful agreement," Obama said, after reminding the UN audience of the end of relations between the two countries starting in 1979, when the U.S.-backed shah was overthrown and militant Islamic students stormed the U.S. Embassy in Tehran, holding 52 Americans hostage for 444 days.
"We should be able to achieve a resolution that respects the rights of the Iranian people, while giving the world confidence that the Iranian program is peaceful," Obama said. "To succeed, conciliatory words will have to be matched by actions that are transparent and verifiable. After all, it is the Iranian government's choices that have led to the comprehensive sanctions that are currently in place."
U.S. officials see Rouhani's election and more moderate stance as a sign of frustration among the Iranians over the sanctions.
Obama sounded encouraged but cautious, and Rouhani's address at times followed suit -- he expressed hope the two countries could patch up decades of grievances.
At other times though, Rouhani's tone turned defensive and confrontational -- echoing in tone if not anti-West vitriol -- the words of his fiery predecessor, Mahmoud Ahmadinejad.
Members of the Israeli UN delegation walked out when Rouhani started his address.
Rouhani spoke of "the persistence of a Cold War mentality and bipolar division of the world into 'superior us' and 'inferior others.' . . . Warmongers are bent on extinguishing all hope."
In answer to Obama's suspicions over his country's nuclear ambitions, Rouhani said Iran has no desire to build nuclear weapons and he doesn't want to quarrel with the United States.
"Commensurate with the political will of the leadership in the United States and hoping that they will refrain from following the shortsighted interest of warmongering pressure groups, we can arrive at a framework to manage our differences," Rouhani said. "To this end, equal footing, mutual respect and the recognized principles of international law should govern the interactions."
Abraham Sofaer, a senior fellow at the Hoover Institution and a former adviser for the U.S. State Department, said Obama's speech was pragmatic.
"I thought it was a much more sober, realistic tone than he had when he came into office and was reaching out to Iran," Sofaer said. He added that Obama is wise to take the carrot-and-stick approach that he has taken with Syria -- acknowledging the country's progress toward disarmament but never taking the military retaliation option off the table.
On Rouhani, Sofaer said the Iranian leader did not differ in substance from Ahmadinejad, a firebrand who never failed to make inflammatory statements from the podium.
"It's the usual stuff," Sofaer said. "I think he's definitely trying to get us to be more cooperative but there's a lot of rhetoric in it that's very similar to Ahmadinejad's rhetoric, that we are the warmongers of the world."
Wednesday's speakers at UN General Assembly
Ollanta Humala, president of Peru
Joseph Kabila, president of the Democratic Republic of the Congo
Enrico Letta, prime minister of Italy
Nicolás Maduro, president of Venezuela
Bronisaw Komorowski, president of Poland
Evo Morales, president of Bolivia
Mariano Rajoy, president of Spain