Negotiations between Iran and the International Atomic Energy Agency (IAEA) on an agreement that would allow tougher inspections of the country's nuclear facilities have come to an end in Tehran.
Iran has until the end of the month to satisfy the agency it has no plans for nuclear weapons.
Iranian President Mohammad Khatami has said the country would do "whatever may be necessary to solve the problem" provided its rights were assured.
Khatami wants Iran to retain its right to have nuclear technology
The talks on an additional protocol which would impose a tougher inspection regime were very intense and lasted two days.
The chief Iranian representative, Ali Akbar Salehi, told the BBC Iran was satisfied with the clarifications the agency had provided on various aspects of the protocol.
He said the results would now be referred to the Iranian leadership for a decision which he expected would take a matter of days, but more than 24 hours.
If so, that would mean a resolution of this important aspect of the Iranian nuclear imbroglio would not be ready in time for the possible visit to Tehran by three European foreign ministers from Britain, France and Germany.
If that visit goes ahead it is expected to start late on Monday, but it depends on the ministers being sure that Iran is ready to comply with all of the IAEA's requirements.
That includes the vital issue of uranium enrichment, which the agency has asked Iran to suspend.
Asked whether Iran was ready to halt uranium enrichment plans, President Khatami said it would do "whatever may be necessary to solve the problems", providing it retained its right to have nuclear technology.
That is where the three European ministers would come in, with assurances that they would help Iran get what it needs to produce nuclear power under safeguards.