WASHINGTON, D.C - Russia made a very direct threat to the United States after the U.S. military shot down a Syrian fighter jet Sunday. 

Moscow warned that U.S. jets west of the Euphrates will now be tracked as potential targets. The U.S. military says they tried to de-escalate the situation before taking down the aircraft. 

"We made every effort to warn those individuals not to come any closer and then the commander made a judgment that there was a threat to the forces that we were supporting and took action," said General Joseph Dunford. 

White House officials say they will work with Russia to re-open the communication lines in Syria, but they warn America will maintain its right to defend itself. 

"I'm also confident that our forces have the capability to take care of themselves," said Dunford. 

"The Russians do not want this conflict to escalate further where US and Russian forces come to blow," added Nick Heras, an analyst for the Center for an American Society. "The new Trump administration is testing Russia's alliance with Iran and the Russians are testing the resolve of the new administration in the sense of how much it wants to invest in the new Middle East's most difficult and brutal civil war." 

Russia and the U.S. are backing opposite sides in the ongoing six-year civil war.