Also known as the rules of war, international humanitarian law grants parties to a conflict the right to use appropriate force to achieve their aims, and the Geneva-based group's assessment is an important reference for those parties to determine how much and what type of force they can use. The assessment also can form the basis for war crimes prosecutions, especially if civilians are attacked or detained enemies are abused or killed.

"We are now talking about a non-international armed conflict in the country," ICRC spokesman Hicham Hassan said.

Previously, the ICRC had restricted its assessment of the scope of the conflict to the hotspots of Idlib, Homs and Hama, but Hassan said the organization had determined the violence has spread beyond those areas.

"Hostilities have spread to other areas of the country," Hassan told The Associated Press. "International humanitarian law applies to all areas where hostilities are taking place."