Hossein Amir Abdollahian said “an oral invitation” had been made “but we have not received a written one,” according to the IRNA report.
He did not say who extended the invitation or when it had been sent out.
The United States and Russia are organizing the conference in Geneva with the intention of bringing representatives of President Bashar al-Assad’s government and of rebel groups to discuss ways to end fighting.
Russia has pushed hard for Iran to be invited to the Geneva conference, insisting it is “a very important outside player.”
On Wednesday, Abdollahian told reporters: “Considering that the Geneva conference is focusing on a political solution, we will study any invitation in a positive light.
“Iran will not allow the fall of the Syrian government,” he said on the sideline of a forum Iran opened in Tehran on Wednesday to discuss its own proposals for ending the conflict in Syria.
Delegations from Russia, Nicaragua, Venezuela, Iraq and Algeria were among some reported 40 countries attending the Tehran meeting.
Earlier, Foreign Minister Ali Akbar Salehi had said, without elaborating, that Iran supports the “negotiations in Geneva.”
He also warned against attempts to further fuel the deadly unrest in Syria, saying such moves will inflict irreparable damage on the international system.