An Iranian aircraft carrying 40 tonnes of "medical aid" arrived in Syria on Thursday, the first of four such shipments destined for Tehran's regional ally, the official IRNA news agency reported.
The cargo which arrived in Damascus early Thursday was to be handed over to the Syrian Red Crescent, the agency said, quoting the Iranian ambassador to Syria, Mohammad Reza Raouf Sheibani.
Sheibani said Thursday's shipment included "medicines and medical equipment" and the subsequent shipments would comprise "food products, ambulances, tents and blankets."
He said the deliveries were being made "in the framework of reinforcing the relations and support of Tehran to this country."
Iran is standing fully behind the Syrian regime of President Bashar al-Assad as it battles armed rebel groups it describes as "terrorists".
Tehran has voiced opposition to any foreign "interference" in Syria, and denied US allegations it is sending arms to Syria.
US officials have said they suspect Iran is providing Assad with arms, electronic monitoring equipment, intelligence and advice on how to crack down on the uprising.
"They are working earnestly to keep Assad in power," General James Mattis, the head of the US military’s Central Command, told a Senate hearing last week, according to The New York Times newspaper.
"The aid from Iran is increasing, and is increasingly focused on lethal assistance," The Washington Post newspaper quoted one unnamed official with access to intelligence reports from the region as saying early this month.
The head of Iran's elite military Quds Force, Brigadier General Qassem Suleimani, has paid at least one visit to Damascus recently, the paper said, citing US officials.