The number of Russian troops currently being deployed to Syria has been called "unprecedented" by an unnamed U.S. official, according to Fox News. "It's beginning to look like Crimyria," the source said. Giant Russian planes known as "condors" have been landing in Syria to drop off troops and armored vehicles.

Russia's Foreign Ministry confirmed Wednesday that the country is assisting the Syrian President Bashar al-Assad and his forces against the opposition. Syria has been locked in civil war for more than four years. White House spokesperson Eric Schultz told reporters that the Obama administration is monitoring the situation.

Iran recently granted Russia permission to use their air space to get into Syria. Russia has been actively supporting Assad in Syria for the length of the country's civil war, according to Yahoo! News, deploying both troops and equipment. 

Bulgaria, by contrast, responded to a request from the Obama administration by shutting of its airspace to Russian planes. The White House has also asked Greece to close its airspace to Russia, according to The New York Times.

"We have encouraged our allies and partners to ask tough questions of Russia's increased military deployments to Syria," State Department spokesperson John Kirby said.