Fresh talks on Iran's nuclear program need to make steady progress in order to convince Washington that Tehran is serious about making concessions, analysts say.
The so-called P5+1 talks that got underway Tuesday in Geneva are bolstered by new optimism, thanks in part to a series of recent conciliatory gestures by Iran's new president, Hasan Rouhani.
Although it is not clear what Iran is prepared to offer, Rouhani and his administration have suggested they are willing to make concrete concessions to prove to the West that Iran's nuclear program is peaceful.
Barry Pavel, the director of the Atlantic Council's Brent Scowcroft Center on International Security, says the talks represent a "very important opportunity," but he does not expect a breakthrough at the outset.
"I don't think you're going to get a deal in the first session," said Pavel in an interview with VOA. "On the other hand, I wouldn't let it drag on too long. Because the more it drags on, the more it smells like previous Iranian and North Korean tactics."
Pavel, an ex-defense policy adviser to U.S. President Barack Obama, said the White House should not ignore the example set by North Korea, which has used talks with the West to buy more time to develop nuclear weapons.
"The North Koreans did a very good job of playing for time, bargaining, ultimately coming to a deal, breaking the deal, and continuing all the time to develop nuclear weapons. And they're assessed to have six to 12 [nuclear weapons] now," said Pavel.
If the U.S. and Iran do not reach a deal after three months, in Pavel's estimation, "then we'll know that they're not serious and that this is continuing to play for time."
Mark Fitzpatrick, the director of the Non-Proliferation and Disarmament Program at the International Institute for Strategic Studies, is reluctant to put a deadline on the talks. But he warns the U.S. and Israel may run out of patience if there is no progress by next summer.
"I think there's probably a window of opportunity that might be six months to one year during which if Iran doesn't agree to restrict its program, I think there'll be more talk of a military option," he said.
Fitzpatrick, who has followed both the North Korean and Iranian nuclear programs very closely, argues there is little need to be worried that Tehran will follow Pyongyang's lead in using the talks as a stalling tactic.
"They're doing that anyway. With or without negotiations, their centrifuges are spinning and they're increasing their capability. So it's far better to have negotiations to at least try to put limits on this program," Fitzpatrick said.
And putting limits on the Iranian nuclear program is as much as can be expected, says Fitzpatrick, who thinks there is no realistic scenario in which Tehran agrees to dismantle its nuclear facilities, as Libya did following Western pressure in the 2000s.
"Yes, of course, the Libya option would be ideal, a process of negotiations with a leader who doesn't have to have anybody within his country raising objections. But [late Libyan leader Moammar] Gadhafi was a dictator, he could agree to deal, and he agreed to dismantle his program."
The situation in Iran is understood to be more complex, with President Rouhani only able to offer that which is approved by Iran's supreme leader, Ayatollah Ali Khamenei. Rouhani insists he has been given full authority by the supreme leader to resolve the nuclear issue.
U.S. officials said they are encouraged by Tehran's more moderate tone, but that they are waiting for concrete actions, and not just words, before they will begin to roll back the economic sanctions that have crippled Iran's economy.