A US military aircraft shot down a Syrian government fighter jet on Sunday shortly after the Syrian plane bombed US-backed fighters in northern Syria, the U.S. military said.
The action was carried out "in accordance with rules of engagement and in collective self-defense of Coalition partnered forces," US Central Command said in a statement.
The incident is the fourth time within a month that the U.S. military has attacked pro-Syrian government forces, according to The Washington Post.
U.S.-led Coalition against the Islamic State (IS) group does not seek to fight Syrian government, Russian, or pro-government forces, but will not hesitate to defend Coalition or partner forces from any threat, said the statement.
About two hours prior to the incident, pro-Syrian government forces attacked the Syrian Democratic Forces (SDF)-held town of Ja'Din, south of Tabqah, wounding a number of SDF fighters and driving the SDF from the town, the statement said.
"Coalition aircraft conducted a show of force and stopped the initial pro-regime advance toward the SDF-controlled town," it added.
The U.S.-led coalition shot down the Syrian warplane over the city of Rasafeh in the southern countryside of Raqqa, while the warplane was carrying out a combat mission against the IS group, said the general-command of the Syrian army.
The Syrian army branded the action as a flagrant aggression, saying the downing of the Syrian war jet by the U.S. coalition testifies the United States' support for terror groups.
The attack aims at undermining the capability of the Syrian army, "the only effective power practicing its legitimate rights in fighting terrorism across the homeland," the Syrian military said in a statement.
"The attack comes at a time when the Syrian army is making strides in the war on the IS terror group, which is collapsing in the Syrian desert thanks to the progress of the Syrian army and allied forces," the statement added.