by Matthew Rusling
WASHINGTON, Sept. 30 (Xinhua) -- The U.S. remains guarded after U.S. President Barack Obama on Friday spoke directly with Iranian President Hassan Rouhani, breaking more than three decades of a communications blackout between the two countries.
In a surprise move, the two leaders spoke via phone before Rouhani's departure from a four-day trip to the UN headquarters in New York, when the newly elected leader publicly denounced the use of nuclear weapons in his address to the UN General Assembly.
Topping a long list of contentious issues between the two countries are U.S.-led economic sanctions which have crippled Iran 's economy, as well as Iran's nuclear program, which Tehran insists is peaceful despite U.S. arguments that it is intended to produce weapons.
"What's been done so far is very measured, very moderate and is not committing (the U.S.) to any particular path yet," Michael O' Hanlon, a senior fellow at the Brookings Institution, the Washington-based think tank, told Xinhua.
After announcing news of the telephone call on Friday, Obama said from the White House that "while there will surely be important obstacles to moving forward, and success is by no means guaranteed, I believe we can reach a comprehensive agreement."
"This is all very hopeful," O'Hanlon said of recent developments, but emphasized that his use of the word "hopeful" was more measured and guarded than the term "optimistic".
While there remain major barriers and challenges to any deal, recent days' talks are "extremely encouraging because it does suggest that in fact there is a genuine will on both sides to cut through the difficulties and to make progress," he said.
David Pollock, a Middle East expert with the Washington Institute for Near East Policy, said that while recent developments are a positive signal, they remain symbolic, as there have been no concrete proposals spelling out terms for an agreement on the nuclear issue or sanctions.
"I think we're at the beginning of what looks to me a new chapter," he told Xinhua, adding that the weeks and months ahead are likely to see more substantive exchanges between the two countries.
Still, Pollock cautioned that the two countries are still in the beginning stages of bilateral relations.
"Some people may get carried away, overly enthusiastic about the new tone. But the question is what's the reality behind the rhetoric," he said, adding that he predicts much of the diplomacy will be conducted in a multilateral framework, rather than a bilateral one.
While Obama said Iran had the right to a "peaceful nuclear program," it remains unknown what Iran's nuclear program would look like, and whether Washington would agree to a deal that permitted Tehran to enrich uranium.
Analysts said one plausible compromise is allowing Iran to keep some of its nuclear enrichment capabilities while limiting any move toward a nuclear weapon, in exchange for lifting many of the sanctions against Tehran.
Obama's phone call followed last week's face-to-face meetings between Kerry and Iran's Foreign Minister Javad Zarif, after which U.S. officials said the two sides made no specific agreements. U.S. officials labeled the talks an "introductory meeting" and emphasized they were a "long way" from any agreement.
During a White House visit on Monday, Israeli Prime Minister Benjamin Netanyahu called on the U.S. to tighten sanctions on Iran if the Islamic republic continues its nuclear program during negotiations.
Obama said Iran would be held to the highest standards in verifying its nuclear program before Washington moved to ease sanctions.
A number of U.S. pundits remain distrustful of Iran, questioning why a country swimming in oil would sacrifice its economy just to keep a nuclear power program, arguing that Iran simply wants to rid itself of the harsh, U.S.-led economic sanctions.