As state-owned Arabic-language television Al-Alam said Iran will demand key changes to the deal, President Mahmoud Ahmadinejad reiterated that Tehran has the right to pursue nuclear technology.
"Without a doubt, if there is no justice problems will not be solved," the presidency's website cited him as telling visiting Turkish Prime Minister Recep Tayyip Erdogan.
"When an illicit regime possesses nuclear arms, one cannot talk about depriving other nations of a peaceful nuclear programme," he said, referring to Israel, widely believed to be the Middle East's sole nuclear-armed power.
"The reality is that the Zionist regime is a threat to all countries ... Your clear stance towards the Zionist regime had a positive effect in the world, especially the Islamic world."
Iranian officials continued to express conflicting views on the draft deal.
"Iran will accept the broad framework of the deal, but wants very important changes in it," Al-Alam said, quoting a source close to Tehran's nuclear negotiating team. It said Tehran will give its response within "48 hours."
State-owned English language television Press TV reported that Tehran will not shift its entire stock of low-enriched uranium (LEU) -- as hinted at by the proposed deal -- indicating Tehran would demand changes to it.
The UN's International Atomic Energy Agency (IAEA), which drafted the deal, refused to comment on the reports, saying it is awaiting Iran's official response.
But EU foreign policy chief Javier Solana welcomed Tehran's reported acceptance and said he hoped to talk to Iranian officials on Wednesday, although he did not think the deal required any great adjustments.
"The deal was a good deal and I don't think this requires fundamental changes," he told reporters after talks with EU foreign ministers in Luxembourg, adding that "it's very difficult to know what it means: important changes."
Since 2006, Solana has been negotiating on behalf of world powers to try to persuade Iran to enter talks on suspending enrichment work in exchange for political and economic benefits.
The Iranian television reports come a day after Foreign Minister Manouchehr Mottaki, in a first official response, said Iran might ship part of its LEU abroad, but buying the fuel from a foreign supplier was still an option.
France says the deal calls for Tehran to export to Russia more than 1,200 kilos (2,640 pounds) of its 3.5 percent LEU for refining up to 20 percent purity to fuel a Tehran research reactor that makes medical isotopes.
World powers back this, as they fear Iran intends to enrich its LEU to even higher levels for use in atomic weapons. Another plus from their perspective is that the Tehran facility is closely monitored by the IAEA.
Tehran says its enrichment drive -- the most controversial aspect of its nuclear project -- is peaceful.
The IAEA drafted the uranium exchange deal during talks held between Iran and France, Russia and the United States earlier this month in Vienna.
Iran was to give its response to the deal last Friday but delayed it until this week amid stiff opposition from some top officials.
Influential hardline MP Mohammad Kosari, a member of parliament's committee on national security and foreign policy, said he "rejects the deal," which he says will also "be rejected by the majlis (parliament) by a high margin."
It was unclear whether parliament's approval was essential for the deal.
But committee chairman Alaeddin Borujerdi said Iran should hand over its LEU in batches as it would help in "confidence-building" with world powers.
"We provide part of 3.5 percent enriched uranium to the party in the deal and once we receive the 20 percent, we give another batch of 3.5 percent," Borujerdi was quoted as saying by ILNA news agency.
"In other words not all the fuel (LEU) will be handed over in one batch."
Iran is estimated to have 1,500 kilos of LEU at its enrichment plant in the central city of Natanz, produced in defiance of three sets of UN sanctions.