Russia warns that it will view U.S.-led coalition aircraft in Syria as targets after a Syrian jet was shot down.
The coalition fighting in Syria says it shot down the Syrian Air Force aircraft on June 18 after it bombed U.S.-backed rebels in Raqqa Province.
"Any flying objects, including planes and drones of the international coalition, discovered west of the Euphrates River will be tracked as aerial targets by Russia's air defenses on and above ground," the Russian Defense Ministry said in a June 19 statement.
Denying that the United States had used a communications channel before the SU-22 bomber was downed, the ministry said it was suspending its interaction with the United States on preventing air incidents over Syria from June 19.
Russia has been a key ally of Syrian President Bashar al-Assad, providing air cover for his forces since 2015.
The U.S.-led coalition against the extremist group Islamic State (IS) said pro-government militiamen attacked units of U.S. partner forces known as the Syrian Democratic Forces (SDF).
The coalition said it "contacted its Russian counterparts by telephone via an established "deconfliction line" to deescalate the situation and stop the firing."
But the Syrian aircraft dropped bombs on SDF positions, it said, and was shot down near the town of Tabqa in the afternoon of June 18 "in accordance with rules of engagement and in collective self-defense of coalition-partnered forces.”
"The coalition does not seek to fight Syrian regime, Russian, or pro-regime forces partnered with them, but will not hesitate to defend coalition or partner forces from any threat," the statement said.
The Pentagon confirmed that the Syrian fighter bomber was engaged by a U.S. F-18 Super Hornet.
A Syrian Army statement said the "flagrant attack” was aimed at undermining “the efforts of the army as the only effective force capable with its allies...in fighting terrorism across its territory."
"This comes at a time when the Syrian Army and its allies were making clear advances in fighting the [IS] terrorist group," it said, adding that the pilot was missing.
Meanwhile, Russian news agencies quoted Russian Foreign Minister Sergei Lavrov as saying on June 19 that the United States should respect Syria's territorial integrity and refrain from unilateral actions in this country.
"As for what is happening 'on the ground' in Syria, we proceed from the assumption that it is necessary to fully respect the sovereignty and territorial integrity in Syria," Lavrov was quoted as saying. "Therefore, any actions 'on the ground,' and there are many participants there, including those who carry out military operations, should be coordinated with Damascus."
Lavrov's deputy, Sergei Ryabkov, described the U.S. strike as another step toward "dangerous escalation."
"We are warning Washington against using similar methods in the future," Ryabkov was quoted by Interfax news agency as saying.
He added that he will meet with U.S. Undersecretary of State Thomas Shannon on June 23 in St. Petersburg to discuss problems in bilateral ties, the news agency reported.
The U.S.-backed SDF fighters are in the process of encircling the city or Raqqa, the IS group’s final major stronghold in Syria.
The Syrian Army has also taken territory from retreating IS in the area as the multifaceted battle in Syria rages on after six years.
The United States and Turkey support differing rebel groups against IS and pro-government forces, while Russia and Iran back Assad’s government.
Lavrov, the Russian foreign minister, said a new round of peace talks on Syria in Kazakhstan's capital, Astana, would take place on July 10.
At the end of the previous round of talks in Astana last month, Russia, Turkey, and Iran on May 4 signed a memorandum calling for the establishment of safe zones in Syria, but some Syrian opposition representatives walked out in protest.
The six-year Syrian conflict has left hundreds of thousands dead and driven more than 11 million people from their homes.
IS fighters are also under pressure in their final major stronghold in Iraq. On June 18, Iraqi security forces launched an operation to fully liberate Mosul, country's second-largest city.
U.S. officials said coalition forces had breached the Old City, where the final IS extremists are clinging to their last positions, using more than 100,000 civilians as human shields.