A US general told AFP on Thursday that between 800 and 900 Islamic State group fighters have been killed since Iraqi-led operations to recapture Mosul from the jihadists began.

"Just in the operations over the last week and a half associated with Mosul, we estimate they've probably killed about 800-900 Islamic State fighters," General Joseph Votel, who heads the US military's Central Command, said in an interview with AFP, speaking from an undisclosed location.