Iran's nuclear chief has taken over as the country's interim foreign minister after President Mahmoud Ahmadinejad abruptly fired his predecessor.

State TV says Ali Akbar Salehi was introduced as the new top diplomat at a function at the Foreign Ministry on Saturday. The sacked minister, Manouchehr Mottaki, refused to attend in an apparent gesture of protest.

Ahmadinejad fired Mottaki on Monday in the middle of an official visit to the African nation of Senegal.

No reason was given, but the president may have wanted to install a figure more personally loyal to him as Tehran resumes critical talks with world powers over its nuclear program.

Salehi will serve as caretaker foreign minister until a permanent replacement is named.