President Donald Trump told American troops on Thursday that U.S.-backed forces in Syria have retaken 100 percent of the territory once held by Islamic State militants, contradicting the commander of the U.S.-allied Syrian Democratic Forces, who said it would take another week.

"We just took over, you know, you kept hearing it was 90 percent, 92 percent, the caliphate in Syria. Now it's 100 percent we just took over, 100 percent caliphate," Trump told troops at Joint Base Elmendorf-Richardson during a refueling stop in Alaska.

Earlier on Thursday, the commander of Syrian Democratic Forces, Mazloum Kobani, said in a video released to the news media that the SDF would be able to announce "the complete victory over Daesh (Islamic State) in a week."