USA officials told Reuters that the us military carried out the air strike on Thursday against militia supported by the Syrian government that posed a threat to us and usa -backed Syrian fighters in the country's south.
Earlier on Thursday the US-led coalition announced it had bombed "pro-Syrian regime forces" near Tanf, a remote base in southern Syria near the Syria-Jordan-Iraq border.
It marked the second time under the Trump administration that the USA has struck out against President Bashar al-Assad's forces with airstrikes and first in the apparent vicinity of United States troops operating inside Syria.
Russia also criticized the strike, with Deputy Foreign Minister Gennady Gatilov Gatilov accusing the US on Friday of violating Syria's sovereignty and alleging the airstrike hit civilians, according to Russian media.
A United States official said on Thursday the attack near the town of At Tanf destroyed at least one tank and a bulldozer, while another official said they followed warning shots by USA aircraft meant to dissuade the fighters from advancing further.
As the Wall Street Journal's Yaroslav Trofimov notes, Thursday's strike is significant not because the US has once again struck Assad's forces, but because it did so in defense of Syrian rebels. "Such actions that were carried out against the Syrian armed forces. this is completely unacceptable, this is a breach of Syrian sovereignty", he said. There were USA advisers operating at the base at the time of the airstrikes.
This "flagrant aggression launched by the worldwide coalition exposes the falsity of its allegation about fighting terrorism and undoubtedly demonstrates the reality of the Zionist-American project in the region", the Syrian official said.
Plans to establish de-confliction zones for Syria were guaranteed by Iran, Russia and Turkey in their most recent peace talks in Astana, Kazakhstan.
"You can not consider the US-led coalition airstrike against pro-government forces on Thursday an accident or a mistake anymore". An exception was the US cruise missile strike that was launched last month in retaliation for Assad's chemical weapons attack that killed 86 people.
A Syrian opposition media group, the Palmyra News Network, said there were casualties from the attack, which destroyed a number of vehicles.
A USA defence official told the AFP news agency that the strike did not signal a strategic shift for the coalition, which has focused on battling IS and has tried to avoid intervening in Syria's civil war.
U.S. defence secretary Jim Mattis denied the destruction of the convoy, which included a number of tanks, marked an escalation in the American role in Syria.
Syria has condemned the strike as a "brazen attack" that undermined claims the alliance is fighting extremists.