It said Solana will meet Iran's chief negotiator Said Jalili to discuss a package of proposals drawn up by six major world powers aimed at ending the nuclear standoff.
There was no immediate confirmation from the EU or Iranian officials.
French President Nicolas Sarkozy, whose country currently holds the rotating EU presidency, had said on Tuesday that Solana would be despatched to Iran for "in-depth discussions" on differences over the package.
The group of six nations — Britain, China, France, Germany, Russia and the United States — last month offered Tehran a package of technological and economic incentives in return for Iran suspending uranium enrichment, a process the West fears could be used to make an atomic bomb.
France said however that in its response to the offer, Tehran had not undertaken to freeze enrichment
And on Wednesday, Iran test-fired a missile it said is capable of reaching Israel, angering the United States amid growing fears that the nuclear standoff could lead to war.
