Turkish Foreign Minister Ahmet Davutoglu had lengthy meetings with Iranian President Mahmoud Ahmadinejad and three other senior officials this week in which the offer was made, the Hurriyet Daily News reported Thursday.
A U.N. proposal calls for Iran to continue its nuclear program but to enrich its uranium -- a step in creating nuclear weapons -- in France and Russia. Iran is insisting on doing it within its own borders.
A senior Turkish diplomat who didn't want to be identified told Hurriyet it wasn't possible to gauge the four officials' response to Turkey's offer in separate meetings.
"The Iranians are inscrutable and there is no single Iran in front of us," he said.
A U.S. diplomat in Washington who didn't want to be identified told Hurriyet there needed to be more momentum.
"Turkey's efforts to get Iran to engage are welcome, but as Prime Minister (Recep Tayyip) Erdogan said last weekend, they have yet to yield results," the official said. "If Iran feels that it can act with impunity, then we'll all have a problem."