"US sanctions re-imposed on Iran in August and November 2018 have had limited effect on Iran’s ability to operate in Syria," the report said.
The United States reinstated sanctions against Iran following the country's withdrawal from the Joint Comprehensive Plan of Action (JCPOA) in May. The first round of sanctions came into force in August, followed by a second round on November 5.
READ MORE: EU Urges Iran to Refrain From Ballistic Missile Development Activities
However, the report added that US Treasury designations imposed in late November against an illicit Russia-Iran oil transfer network in Syria could have an effect on the Iranian regime’s funding of terrorist organizations.
US sanctions prohibit material support to the government of Syrian President Bashar Assad, including shipments of oil to Syrian government-controlled ports, as well as material support to designated terrorist groups.