Brazil and Turkey helped broker an agreement under which Iran agreed to send low-enriched uranium abroad, reviving a fuel swap plan drafted by the United Nations with the aim of keeping Iran's nuclear activities in check.

Washington regards that deal as a delaying tactic by Iran, and the five permanent members of the UN Security Council agreed on a draft resolution to impose new sanctions on Iran.

"Of course there need to be reassurances, discussions - many things still need to happen. It's difficult but there is a way out," Amorim told foreign correspondents in his office.

"You need to give it some time to work."

If the sanctions were approved, Iran would cancel the accord with Turkey and Brazil, a member of Iran's Parliament said.

Several countries were still open to the possibility of pursuing talks at the same time as imposing sanctions on Iran, said Amorim.