The incident occurred in the same vicinity as previous conflicts with pro-regime forces, near the combat outpost in At-Tanf, where a contingent of US and coalition advisers are supporting a force to fight the Islamic State, also known as ISIS.
"There has been neither a Security Council decision, nor a request from the official authorities of the Syrian Arab Republic as a sovereign state", Russia's Interfax news reported. "If the regime continues attacking our positions in Raqqa province, we will be forced to retaliate", SDF spokesman Talal Silo said.
"The Coalition's mission is to defeat ISIS in Iraq and Syria", OIR reiterated in a statement on June 18 after a us fighter jet shot down a Syrian Air Force SU-22 jet that was bombarding coalition-backed Syrian Democratic Forces.
The remarks came amid questions whether the strike had been effective.
"West of the Euphrates" is a line that has been used by Ankara for over a year, concerned about YPG/PKK militants advancing to form a continuum in the area they control along the Turkey-Syria border, which Turkey says is part of preparations to officially separate a PKK-controlled Kurdish region from Syria. The 48-hour truce that had started there at noon Saturday was supposed to be extended.
Meanwhile, in northern Syria, the ISIS stronghold of Raqqa is now under siege by coalition-backed Kurdish forces, who, like most of the militias supported by the US -led coalition as part of Operation Inherent Resolve, are considered an enemy of the regime.
The U.S. military said it had shot down an armed, Iranian-made drone that had been bearing down on its forces near a garrison in Syria's southeast on Tuesday, in the latest sign of increasingly frequent confrontation with Damascus and its allies, APA reports quoting Reuters. The Western intelligence source said it was "unquestionably Iranian".
"The situation is back as it was in Daraa city and fighting is ongoing", said Daraa-based opposition activist Ahmad al-Masalmeh. The conflict quickly descended into a civil war, which has since left at least 400,000 people dead.
Two top Revolutionary Guard commanders said that the strikes were meant to send a message to the perpetrators of militant attacks in Tehran last week - claimed by Islamic State - that killed 18 people, as well as their supporters.
Sharif says the missile launch reflects Iran's "military power" though Iran has no intention of starting another war.
In six years of civil war that has ravaged Syria, it was the first time the United States has shot down one of the country's planes.
Washington also described those strikes as self-defense.
The U.S. military said it shot down an Iranian-made, armed drone in southern Syria on Tuesday, marking the third time this month that that the U.S. has downed aircraft affiliated with Syrian President Bashar Assad's government.
The US-led worldwide coalition later confirmed the incident in a statement, saying the armed drone was downed "after it displayed hostile intent and advanced on Coalition forces" that "were manning an established combat outpost to the northeast of At Tanf where they are training and advising partner ground forces in the fight against ISIS". Also, Iran fired several ballistic missiles Sunday night at IS positions in eastern Syria.
The U.S. military meanwhile confirmed Tuesday that top IS cleric Turki al-Binali was killed in a coalition airstrike on May 31, in Mayadeen, Syria.