On Monday, the IAEA confirmed Tehran had notified the U.N. nuclear watchdog of its plans to produce higher-grade fuel, and said it would damage chances of saving the fuel supply deal.
But Foreign Ministry spokesman Ramin Mehmanparast said: "We're still prepared, if our requirements are met, to carry out this swap ... any time they are ready this can be done."
(Additional reporting by Parisa Hafezi and Hossein Jaseb in Tehran and Chris Buckley in Beijing; Writing by Fredrik Dahl; editing by Dominic Evans)