The top U.S. commander for the Middle East said Thursday that the United States will keep the current 2,500 troops in Iraq for the foreseeable future, and he warned that he expects increasing attacks on U.S. and Iraqi personnel by Iranian-backed militias determined to get American forces out.

Marine Gen. Frank McKenzie said in an interview with The Associated Press at the Pentagon that despite the shift by U.S. forces to a non-combat role in Iraq, they will still provide air support and other military aid for Iraq’s fight against the Islamic State.

Noting that Iranian-backed militias want all Western forces out of Iraq, he said an ongoing uptick in violence may continue through December.