Russia's Defense Ministry says it would view as targets any flying objects over Syria in the areas of the country where its warplanes operate, Russian news agencies reported on June 19.
The statement came after a U.S. warplane shot down a Syrian Army jet on June 18 in the Raqqa region.
Washington has said the Syrian plane had dropped bombs near the U.S. partner forces known as the Syrian Democratic Forces (SDF), while Damascus said the plane was downed during a mission against Islamic State (IS) militants.
The Russian Defense Ministry also said that it was suspending its interaction with the United States on preventing air incidents over Syria from June 19, the agencies reported.
The United States did not use its communication channel with Russia ahead of the downing of the Syrian government warplane, the ministry was quoted as saying.
A U.S. military statement earlier said the coalition had "contacted its Russian counterparts by telephone via an established 'deconfliction line' to deescalate the situation and stop the firing."
"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.
'Collective Self Defense'
A U.S. jet shot down a Syrian government warplane after it attacked forces fighting against the Islamic State (IS) militant group on the southern edge of Raqqa, the U.S.-led coalition in Syria says.
The Pentagon said the Syrian fighter jet was shot down "in accordance with rules of engagement" and "collective self-defense."
The U.S.-backed SDF fighters are in the process of encircling the city of Raqqa, the IS group's final major stronghold in Syria.
A Syrian Army statement said the plane crashed, and the pilot was missing in the incident near the village of Rasafah.
The "flagrant attack was an attempt to undermine the efforts of the army as the only effective force capable with its allies...in fighting terrorism across its territory," it said.
"This comes at a time when the Syrian Army and its allies were making clear advances in fighting the [IS] terrorist group," it added.
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 the Interfax news agency as saying.
He added that he would be meeting 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 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 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.