The chairman of the Senate Armed Services Committee says the panel is investigating complaints that senior defense officials altered intelligence reports on the Islamic State and other militant groups in Syria to exaggerate progress being made against the terrorist group.

Gen. Lloyd Austin, the top U.S. military commander for the Middle East, is facing questions Wednesday from committee members about allegations that intelligence assessments were manipulated.

In his opening statement, Austin updated the committee on conditions in Iraq and Syria.

Austin says the Iraqis must recruit and retain new forces or gains will be limited against the Islamic State.