The civil war in Syria “dangerously exacerbated” after Russia launched airstrikes, the United States said Wednesday. Washington also blamed Moscow for targeting opponents of Syrian President Bashar Assad and displacing thousands of civilians in the war-stricken country.

Addressing the House Committee on Foreign Affairs, U.S. Assistant Secretary of State for Near Eastern Affairs Anne Patterson said Moscow was only strengthening the Assad regime instead of fighting the Islamic State group. Furthermore, the Russian air campaign killed several civilians in attacks on civil defense members, hospitals, centers of displaced people and ambulances, Patterson claimed, according to Agence France-Presse (AFP).

"Russia's military intervention has dangerously exacerbated an already complex environment," Patterson said. “We know that Russia's primary intent is to preserve the regime. … Despite our urging, Moscow has yet to stop the Assad regime's horrific practice of barrel bombing the Syrian people,” Patterson said, adding that the situation in Syria required a "full court press to end the war and get to a political settlement," according to AFP.

Patterson’s comments came after Syrian state media reported Wednesday the country’s army recaptured the only road linking the northern city of Aleppo to central Syria from the militants.

Russia launched first airstrikes in Syria late September saying it would target the Islamic State group. However, the U.S. expressed concern over Kremlin’s move in a four-year-old war that has already pulled in America and its allies. After Moscow started the air campaign, U.S. Defense Secretary Ashton Carter said Russian airstrikes in the troubled country were like “pouring gasoline on the fire.”

“It does appear that they were in areas where there probably were not ISIL forces, and that is precisely one of the problems with this whole approach,” Carter said at the time, referring to the terror group by the name the U.S. government uses to describe it.

The Central Intelligence Agency reportedly started an undercover operation in 2013 to arm, fund and train a Assad’s rebels. since then, the CIA has provided training to about 10,000 fighters.