It said Solana, in a letter addressed to Iran's top nuclear negotiator Saeed Jalili, said the major powers wanted to resolve the dispute through diplomacy. The letter was handed to Iran's embassy in Brussels Thursday.
"In the letter Solana wanted fresh talks to remove minor outstanding issues about Iran's nuclear work. Solana also insisted on his commitment to resolve the issue through diplomacy," ISNA said.
The West fears the Islamic Republic, the world's fourth-largest oil producer, is seeking to build nuclear arms.
Iran says it only wants to generate electricity and has repeatedly ruled out halting uranium enrichment, which can have both civilian and military purposes. Its refusal to do so has drawn three rounds of U.N. sanctions since 2006.
An EU official said Solana had mentioned the letter.
"Solana mentioned to EU deputies this week that he had sent a letter to Iran," the official told Reuters in Brussels. He gave no further details.
Solana, representing the United States, Britain, France, Germany, China and Russia, and Jalili last discussed Tehran's nuclear program by telephone in August.
The six powers offered in June to hold off from seeking further sanctions if Iran freezes expansion of its nuclear work.
Iran responded with a non-committal letter and Western countries said they would look at stepping up sanctions on Tehran.
Russia and China, which gave reluctant backing to three previous sanctions resolutions that included asset freezes and travel bans on specific Iranian individuals and companies, are not supporting further U.N. measures for the time being.
In the letter Solana said Iran's "questions and concerns" about the major powers' offer were "understandable," ISNA reported.
The U.N. Security Council in September passed a resolution that again ordered Tehran to halt enrichment but imposed none of the new sanctions Washington and its allies want.
Iran has dismissed the latest resolution as "unconstructive" and has made clear it would not bow to international pressure to halt enrichment.
A senior Iranian official called on U.S. President-elect Barack Obama to show goodwill and remove "cruel" sanctions imposed on the Islamic Republic.
Obama has said he would harden sanctions on Iran but has also held out the possibility of direct talks with U.S. adversaries to resolve problems, including the dispute over Tehran's nuclear ambitions.
(Additional reporting by Mark John in Brussels)
(Writing by Parisa hafezi, editing by Philippa Fletcher)
