The Russian Defense Ministry announced on June 19 that Russia's defenses would track the US-led coalition's warplanes and drones west of the Euphrates in Syria after a United States warplane had shot down a Syrian Su-22 fighter.
The Iranian-made Shaheed-129 drone was shot from the sky in the same location where another pro-regime drone dropped a dud bomb near coalition forces before it was shot down by an unidentified USA aircraft down on June 8, the US military operation fighting ISIS, Operation Inherent Resolve (OIR), said in a statement.
Soon after Russian Federation brought its military support for Syrian President Bashar Assad, in 2015, Moscow and Washington signed a memorandum to prevent air clashes between them in Syria.
The US-led coalition has been conducting airstrikes against what are said to be the positions of Daesh terrorists inside Syria since September 2014 without any authorization from the Damascus government or a United Nations mandate.
In an indirect reference to Iranian-backed forces that have been gathering in the eastern desert region, a USA -led coalition statement cited a recent escalation of tensions and said it would not "tolerate any hostile intent and action of pro-regime forces".
The downing came after the Syrian government's SU-22 jet dropped bombs near US-backed fighters combating Daesh.
Moscow has now suspended an incident hotline meant to prevent confrontations in Syria's crowded air space, and warned it could consider US-led coalition planes "targets".
The staunch USA ally in September said it would widen the scope of targets in the air war against IS by allowing its pilots to strike jihadist support and logistics resources in Iraq and Syria.
Earlier this month, the US shot down another pro-regime drone in the same area after it dropped munitions near coalition forces.
The coalition said it contacted Russian commanders to set up a "de-confliction line" to prevent the fighting from worsening.
US-Russia tensions are high in Syria after the Kremlin warned it would target any US-led coalition's aircraft flying west of the Euphrates River.
That warning came after the U.S. shot down a Syrian military plane.
Australia joined the US-led coalition in Syria in September 2015, but did not carry out any operations in the country between March and May this year, according to the defence department. US warplanes launched three other airstrikes against the forces there.
The recent strikes and military support from Russian Federation against the Islamic State group has been a major support for the Syrian government's efforts to eradicate terrorist groups from their borders.
Syrian and Iranian-backed ground forces also have been gathering in the desert region.