"Mr. Solana proposed two different dates for his visit to Tehran I am considering," Mottaki told reporters without setting a date for the visit by European Union foreign policy chief Javier Solana.
"I think he will pay a visit to Tehran soon."
Mottaki said on Wednesday his government had agreed in principle to a visit by Solana.
"Solana has given us a message that he wants to travel to Iran to deliver the package and we have agreed to the principle of the visit," Mottaki was quoted as saying by the official IRNA news agency.
A US official said last week that six world powers have completed the details of a "refreshed" offer they will present to Iran to try to end the long-running nuclear standoff.
The six powers are the five permanent members of the UN Security Council — the United States, Russia, China, Britain and France — plus Germany.
The United States has pursued a two-track policy of UN and other sanctions on Iran for its failure to halt the enrichment of uranium, while also holding out offers of economic and other incentives if it stops such work.
The enrichment process is used for power generation but at highly refined levels can also be used to build the core of a nuclear weapon.
Many in the West fear that the Islamic republic is trying to covertly develop an atomic bomb behind the screen of a civilian nuclear programme. Iran insists it only wants to produce electricity.
