NEW YORK (CNN) -- The outgoing head of the U.N. nuclear watchdog agency said a question of timing is the top issue delaying a nuclear deal between Iran and international powers.
"The major issue, the rocky issue which is facing us, is the sequencing," Mohamed ElBaradei, the director-general of the International Atomic Energy Agency, told CNN's Christiane Amanpour on Thursday in an exclusive -- his first television one-on-one exit interview. He is stepping down at the end of the month.
A draft agreement has been supported by the United States, France and Russia. It calls for Iran to ship low-enriched uranium outside the country, possibly to Russia, to be converted into fuel rods.
The material then would be shipped back to the Tehran research reactor that produces isotopes for use in medical treatments. ElBaradei revealed that under the deal Iran would get the converted fuel back by the end of 2010.
But, he said, Iran wants to ship out low-enriched uranium and simultaneously get back more enriched material, a "simultaneous" swap that would enable it to receive the fuel more quickly.
Iran wants "guarantees" and is concerned about trust, ElBaradei said.
It doesn't want to send away its low-enriched uranium and risk not receiving the converted material for its research reactor if the deal breaks down. ElBaradei did not say from where Iran might get fuel immediately.
He said the deal reached in Vienna, Austria, serves as a "huge opportunity" to defuse the tension between international powers, who suspect Iran wants to develop nuclear weapons, and Iran, which says it plans to develop nuclear power solely for peaceful purposes.
ElBaradei said "people need to look at the big picture," which includes an Obama administration willing to engage with Iran, and an Iranian regime also interested in engagement.
"There's a grand bargain possibly here," he said.
For the United States, he said, shipping the material out of the Islamic republic would symbolize a defusing of the crisis -- the assumption that Iran is accumulating material to be used in a weapon.
"That perception would completely be eliminated if we could remove the stuff out of Iran. And that would give Barack Obama and his administration the sign he needs to negotiate with Iran in a calmer environment," ElBaradei said.
He said Obama has made it clear that "he's ready to negotiate the whole nuclear issue, the trade, technology, security issues."
"Iran is absolutely needed in Afghanistan, in Iraq, in Syria, in Lebanon, in Palestine. So it's a win-win situation for everybody, and I see that everybody understands that. But there is still this animosity, mistrust, pride, if you like, dignity. And we have to overcome that."
Iran has said it has had negative experiences in the past with such deals.
But in this instance, the international community would be taking custody of Iran's material, and Americans are a party to the international agreement that the project would move forward -- potentially increasing trust between Iran that the United States.
"The United States is trying to be advocate of what's possible and looking into all sorts of different options, including possibly the U.S. direct involvement in the package," said ElBaradei, who noted that the international community is looking for a third country that can store the Iranian material until they get the fuel.
"Turkey, for example. I mean, we haven't talked to Turkey, but I'm sure they would be happy to be an agent, to keep the materials in under IAEA custody. So we are and I am looking for every possible opportunity. And I must say the Russians are doing the same; the Americans are doing the same."
A deal would underscore ElBaradei's belief that the "only way to resolve issues is through meaningful engagement" as opposed to sanctions -- which many times would have the unintended effect of making the regimes more popular in their home countries.
In September, Iran revealed the existence of a previously unknown nuclear facility near the city of Qom.
ElBaradei said Iran violated its obligations to the International Atomic Energy Agency and the international community by not reporting the existence of the facility. But Iran is now working with the IAEA, he said, adding that the facility is in the early stages of construction.
"We have got quite a good cooperation. It's still a facility under construction. There is no equipment, there is no nuclear material," he said.
Noting his comment that the facility is in "a hole in the mountain," ElBaradei was asked what he thinks it's for.
"Well, they said it's for enrichment. It's for enrichment and to protect their technology. I mean, what they told me is that this is a passive defense, as they say, in case we were bombed, we need to protect our technology. So this was meant to be a small enrichment facility."
ElBaradei also said the IAEA doesn't have the highest level of technology and clout available at all times to do its job. If the agency doesn't get more technology, human resources and legal authority, "we will continue to be a sleepy watchdog."
"The system is facing a lot of challenges ... (and) we have not really had the tools to address the new challenges. We don't have the technology we need, the satellite imaging we need. We don't have the labs that allow us to do environmental samplings which are modern-day tools for certification. We don't have the legal authority in many countries."
ElBaradei, an Egyptian national, was asked about the prospects of one day seeking the Egyptian presidency. He said he'd only consider that if there were "written guarantees" that it would be "a free and fair election."