Iranian state television quoted Foreign Ministry spokeswoman Marzieh Afkham as saying Wednesday that Iran's pick, Hamid Abutalebi, is one of the country's best diplomats. Afkham also says Abutalebi previously received a U.S. visa.
Abutalebi previously served at Iranian diplomatic missions in Australia, Belgium and Italy.
American officials objected to the selection of Hamid Abutalebi because of his alleged participation in a Muslim student group that held 52 Americans hostage in the 1979 seizure of the U.S. Embassy in Tehran.
White House spokesman Jay Carney said Tuesday the U.S. told Iran the choice was "not viable." The U.S. approved a bill Monday barring Abutalebi from entering the U.S.