Russia's defense ministry on Saturday slammed the US over plans to maintain and boost its military presence in eastern Syria, saying its actions were motivated by a desire to protect oil smugglers and not by real security concerns.
In a statement, the ministry said Washington had no mandate under international or US law to increase its military presence in Syria and said its plan was not motivated by genuine security concerns in the region.
"Therefore Washington's current actions - capturing and maintaining military control over oil fields in eastern Syria - is, simply put, international state banditry," it added.
US Defense Secretary Mark Esper said on Friday Washington would send armored vehicles and troops to the Syrian oil fields mainly in Deir Ezzor province in order to prevent them from falling into the hands of ISIS militants.
Some 200 US troops are currently stationed there.
His comments came after President Donald Trump earlier this month pulled some 1,000 US military personnel out of northeast Syria, a move that prompted Turkey to launch a cross-border incursion targeting the Kurdish YPG, a former US ally against ISIS.
US troops and private security companies in eastern Syria are protecting oil smugglers who make more than $30 million a month, Russia’s defense ministry statement said.
Moscow has further bolstered its position in Syria following the US withdrawal from the northeast of the country, negotiating a deal this week with Turkey's President Recep Tayyip Erdogan to help remove the Kurdish fighters from within a 30 km strip along the Syrian-Turkish border.