Iran’s nuclear chief says his country is ready to enter negotiations with the United States, Russia and France on a possible nuclear fuel agreement.

Ali Akbar Salehi was quoted Friday by Iran’s Mehr news agency as saying Iran would be ready to enter talks with the countries that make up the Vienna Group within the next few days.

Salehi said: “We are ready even in the next few days to start negotiations with the other parties.”

He said uranium talks with the so-called Vienna Group, comprising the United States, Russia and France, will be held in Vienna, where U.N. atomic watchdog the International Atomic Energy Agency is based.

The Vienna Group has raised questions about a proposal put forward by Iran, Brazil and Turkey concerning a fuel swap. The May 17 proposal, known as the Tehran Declaration, stipulates that Tehran would send 1,200 kilograms of its low-enriched uranium to Turkey in return for 20 percent high-enriched uranium, to be supplied at a later date.