Updated

The top U.S. military commander for Afghanistan says he's asked for greater flexibility in how quickly he pulls troops out of Afghanistan and where he can position them around the country.

Army Gen. John Campbell provided few details Wednesday during testimony before the Senate Armed Services Committee. He said, however, he's presented military leaders with several options that would allow him to better continue training and assisting Afghan forces, particularly through this summer's peak fighting season.

Current plans call for the U.S. to go from about 10,800 troops there now to 5,500 by year's end.

Campbell also expressed concern about the potential emergence of Islamic State group fighters in Afghanistan. He says the group has a nascent presence there, mostly marginalized Taliban fighters.