The Pentagon is warning Russia to stop bombing to support the Syrian regime’s offensive in Syria’s contested Idlib province as the United States launched strikes deep into the region aimed at al-Qaeda leaders this weekend.

The US Central Command targeted a jihadi camp Saturday, reportedly killing 40 militants just hours before a Russian-backed unilateral cease-fire took effect; this was the second such US attack in northwest Syria this summer. But as the United States moves against the militants' presence, the Defense Department says Russia has repeatedly violated its 2018 deescalation deal with Turkey by targeting infrastructure in the region.

“Not even a year has passed since Turkey and Russia signed their Idlib Memorandum of Understanding, and the Russians are already providing support to the Regime’s offensive campaign to retake parts of Idlib, bombing critical civilian infrastructure and creating a humanitarian catastrophe,” Michael Mulroy, the Pentagon’s deputy assistant secretary for the Middle East, said in a statement provided to Al-Monitor. “We continue to call upon the Syrians and Russians to cease their offensive into Idlib and return to the agreement they made with the Turkish government in October of last year.”

Mulroy has also warned against the potential of mass and collateral damage in a possible Russian-led siege against Idlib, similar to what occurred in Aleppo three years ago. The Pentagon sees Russian support to the regime of President Bashar al-Assad “as the center of its approach” to dislodge US military power in the Middle East at a low cost, Mulroy added; part of this approach is Russia having a naval facility in the Syrian city of Tartus and a separate coastal air base.