The main border crossing between Iraq and Syria, the city of Abu Kamal on the Syrian side and al-Qaim on the Iraqi side, is the last major territorial possession of ISIS, and the next big target for both Syria and Iraq’s militaries.

With those offensives likely to happen soon, ISIS is building up its defenses around the area, pushing more forces into the area while, according to US officials, ISIS leaders are being evacuated to smaller towns inside Syria that they still control.

ISIS still holds substantial territory in Syria, mostly in Deir Ezzor Province. They’ve been losing all the big cities and towns, along the Euphrates River, with Syrian military pushing on the river’s south shore, and Kurdish fighters taking the north shore.

US officials are suggesting an attack on Abu Kamal would be up to the Kurds to decide, but the Syrian military is likely to get there first. The Iraqi Air Force has already been dropping leaflets in al-Qaim in anticipation of an attack on that side of the border.