The area, where only Syrian forces will be allowed, will stretch for 30 kilometers from the Jordan border.
Asharq Al-Awsat quoted senior officials who listed three principles agreed upon in the memorandum of understanding between the three countries: no presence of non-Syrian forces inside the safe zone, a ceasefire between the Syrian regime and the rebel factions, bringing in humanitarian aid while returning refugees who fled to Jordan back to the area.
Meanwhile, the American administration is expecting the fall of ISIS' stronghold in the city of Raqqa in Syria, estimating the next step would be a direct conflict against Syrian President Bashar Assad and his Iranian patrons.
According to a report in the Washington Post, White House officials are pressuring the Pentagon to act in light of the advance of Assad and Iranian forces toward the desert in east Syrian. The administration is worried regime forces will get in the way of US-led coalition efforts in the area to cut ISIS' territorial continuity along the Euphrates River going into Iraq.