Daily Express
State Department spokesman Mark Toner tore apart Moscow's attempts to help deliver humanitarian aid to areas of the war-ravaged Middle Eastern country.
The condemnation comes after Russian Foreign Minister Sergei Lavrov supported calls by the International Syrian Support Group to send more aid to Syria.
The US State Department said Moscow had supported the effort to send aid to Syria
Criticising the Kremlin, Mr Toner said: "We are obviously disappointed, to put it mildly, that … Russia has not taken any demonstrable steps to support the International Syria Support Group's call for the delivery of humanitarian relief by air.
"The Russians were there in Vienna. And they committed to this deadline as well. So, you know, they can also step up and apply pressure."
Mr Toner claimed Moscow was well–placed to help with aid delivery and blasted its inaction towards aiding Syria.
He added: "Russia actually has air assets on the ground in Syria and ostensibly has the permission of the Syrian government to fly.
"They're aware of our concerns.
"They are on the ground with air assets in Syria and are able to carry out these kinds of operations."
The State Department spokesman took aim at Syrian President Bashar al-Assad and said he had prevented "full access to the delivery of humanitarian assistance" and removed medicine and food from some of the convoys
Mr Toner said Assad is "sadly mistaken if he thinks there's a military solution" after the Syrian President pledged to win back "every inch" of Syrian territory.
Tensions have been simmering between Russia and the US in recent months as threats of another Cold War escalate.
President Barack Obama raised concerns last month about Russia's "growing aggressive military presence" after Mr Putin threatened to "neutralise emerging threats".