The State Department on Thursday acknowledged that the Russian helicopters Secretary of State Hillary Clinton earlier claimed would “escalate quite dramatically” the Syrian conflict were actually returning to Syria after being refurbished.

State Department spokeswoman Victoria Nuland said the U.S. is nevertheless concerned that the helicopters will be used by President Bashar Assad's regime to kill civilians.

Clinton has recently claimed that Russia supplies attack helicopters to Syria, but Russian Foreign Minister Sergei Lavrov on Wednesday dismissed the claims saying Russia was “completing the implementation of contracts that were signed and paid for a long time ago” and adding that the contracts "concern exclusively anti-aircraft defense.”

“We are not delivering to Syria, or anywhere else, items that could be used against peaceful demonstrators,” Lavrov went on. “In this we differ from the United States, which regularly delivers riot control equipment to the region, including a recent delivery to a Persian Gulf country. But for some reason the Americans consider this to be fine," Lavrov said.