“This is unacceptable, without an appropriate request from the Syrian authorities it will be another flagrant violation of international law.”

Earlier in the day, The Wall Street Journal reported, citing US officials, on US plans to deploy a small number of ground troops in Syria embedded among Kurdish troops, or what is considered by the US to be a so-called moderate opposition, to fight against the Islamic State.On Tuesday, US Defense Secretary Ashton Carter said the Pentagon had not ruled out conducting attacks on the ground against ISIL terrorists.

According to Matvienko, the United States “has already flagrantly violated international law” by organizing an air operation in Syria without an approval from the UN Security Council or Damascus.

Syria has been in a state of civil war since 2011, with government forces fighting on multiple fronts, against opposition factions aiming to overthrow Syrian President Bashar Assad, and extremist groups, including ISIL.Since the beginning of the war, the United States and some of its allies have supported “the moderate” Syrian opposition and called for Assad’s resignation, while Russia recognized Assad as the only legitimate Syrian authority.

On September 30, Russia began an anti-ISIL air campaign in Syria at Assad’s request.