The U.S. Treasury Department has targeted six individuals and three entities that it says are part of an Iranian-Russian network providing millions of barrels of oil to the government of Syrian President Bashar al-Assad and funding the militant groups Hamas and Hizballah.

The Treasury's Office of Foreign Assets Control said on November 20 that Russia facilitated the delivery of Iranian oil to Syria, and that a variety of mechanisms were used in an attempt to conceal the shipments and payments.

"Today we are acting against a complex scheme Iran and Russia have used to bolster the Assad regime and generate funds for Iranian malign activity," Treasury Secretary Steven Mnuchin said in a statement.

Leonid Slutsky, the chairman of the Foreign Affairs Committee in the lower house of Russia's parliament, the State Duma, called the latest U.S. sanctions "absolutely illegal and unlawful."

Russia and Iran have given Assad crucial support throughout the war in Syria, which began with a government crackdown on protesters in March 2011. The conflict has left more than 400,000 people dead, displaced millions, and devastated many historical sites across the country.

Those added to the U.S. list of sanctioned entities and persons include Syrian national Mohammad Amer Alchwiki and his Russia-based company, Global Vision Group, Russia's state-owned company Promsyrioimport, and its deputy director, Andrei Dogayev, who is a Russian citizen, the Treasury said.

The other targets are Iran's Tadbir Kish Medical and Pharmaceutical Company, Iranian nationals Rasoul Sajjad and Hossein Yaghoubi Miab, Syrian national Hajji Abd al-Nasir, and Lebanon national Muhammad Qasim al-Bazzal.

The move blocks any of their assets under U.S. jurisdiction and warns non-U.S. institutions against conducting transactions with them.

By RFE/RL