A Russian Sukhoi Su-35 bomber lands at the Russian Hmeimim military base in Latakia province, in the northwest of Syria on May 4, 2016.
Syria's conflict erupted in 2011 after anti-government protests were put down. Fighting quickly escalated into a multi-faceted war that has killed more than 270,000 people and forced millions from their homes. / AFP / Vasily Maximov / MOY        (Photo credit should read VASILY MAXIMOV/AFP/Getty Images)
VASILY MAXIMOV/AFP/Getty Images
A Russian Sukhoi Su-35 bomber lands at the Russian Hmeimim military base in Latakia province, in the northwest of Syria on May 4, 2016. Syria's conflict erupted in 2011 after anti-government protests were put down. Fighting quickly escalated into a multi-faceted war that has killed more than 270,000 people and forced millions from their homes. / AFP / Vasily Maximov / MOY (Photo credit should read VASILY MAXIMOV/AFP/Getty Images)
Now playing
03:17
Russia threatens to down U.S. jets in Syria
Now playing
02:27
Exclusive: Inside Syria's demilitarized zone
Vaciha Turki Al Omar, 30, has been in Idlib for seven months. She on the hill overlooking the sprawling refugee camp with her kids. "We can try to fight but the kids are our weakness so we must run away," she says.
Gul Tuysuz
Vaciha Turki Al Omar, 30, has been in Idlib for seven months. She on the hill overlooking the sprawling refugee camp with her kids. "We can try to fight but the kids are our weakness so we must run away," she says.
Now playing
03:54
Major rebel stronghold in Syria under threat
Lead Martin Savidge on Florence live Jake Tapper_00022318.jpg
Lead Martin Savidge on Florence live Jake Tapper_00022318.jpg
Now playing
04:15
Cat 3 Florence coming in like a 'Mike Tyson punch'
idlib syria frontlines pleitgen 2
OTTO, CLAUDIA/CNN
idlib syria frontlines pleitgen 2
Now playing
01:49
CNN travels to the front lines of Idlib
rebuild syria
CNNI
rebuild syria
Now playing
02:15
Syrians rebuild war-torn historic city of Homs
White Helmets
Now playing
02:10
White Helmets evacuated into Jordan by Israel
Reuters
Now playing
00:56
Girl's new prosthetic legs replace tin cans
syria golan heights fleeing lee pkg_00002705.jpg
CNN
syria golan heights fleeing lee pkg_00002705.jpg
Now playing
02:15
Thousands flee toward closed borders
A day in the life of an artist-turned-barber Syrian refugee living in the Zaatari Refugee Camp in Jordan.
CNN
A day in the life of an artist-turned-barber Syrian refugee living in the Zaatari Refugee Camp in Jordan.
Now playing
04:03
A day in the life of a Syrian refugee
CNN
Now playing
02:20
CNN goes inside refugee camp after airstrikes
airstrike syria
CNN
airstrike syria
Now playing
01:29
Video reportedly shows airstrike in Syria
US President Donald Trump addresses the nation on the situation in Syria April 13, 2018 at the White House in Washington, DC. Trump said strikes on Syria are under way.  / AFP PHOTO / Mandel NGAN        (Photo credit should read MANDEL NGAN/AFP/Getty Images)
MANDEL NGAN/AFP/Getty Images
US President Donald Trump addresses the nation on the situation in Syria April 13, 2018 at the White House in Washington, DC. Trump said strikes on Syria are under way. / AFP PHOTO / Mandel NGAN (Photo credit should read MANDEL NGAN/AFP/Getty Images)
Now playing
01:02
Trump's message to Iran and Russia
Vucci/AP/SANA/Nikolsky/Getty Images
Now playing
01:42
Could the Syrian war lead to a US-Russia conflict?
This image released early Sunday, April 8, 2018 by the Syrian Civil Defense White Helmets, shows a child receiving oxygen through respirators following an alleged poison gas attack in the rebel-held town of Douma, near Damascus, Syria. Syrian rescuers and medics said the attack on Douma killed at least 40 people. The Syrian government denied the allegations, which could not be independently verified. The alleged attack in Douma occurred Saturday night amid a resumed offensive by Syrian government forces after the collapse of a truce. (Syrian Civil Defense White Helmets via AP)
Syrian Civil Defense White Helmets/AP
This image released early Sunday, April 8, 2018 by the Syrian Civil Defense White Helmets, shows a child receiving oxygen through respirators following an alleged poison gas attack in the rebel-held town of Douma, near Damascus, Syria. Syrian rescuers and medics said the attack on Douma killed at least 40 people. The Syrian government denied the allegations, which could not be independently verified. The alleged attack in Douma occurred Saturday night amid a resumed offensive by Syrian government forces after the collapse of a truce. (Syrian Civil Defense White Helmets via AP)
Now playing
01:59
Syrian attacks escalate tensions among global powers
Now playing
00:47
Families bused out of chemical attack city

Story highlights

Russian statement comes day after US Navy jet shoots down Syrian warplane

Defense official: Threat level has escalated in Syria

Moscow CNN —  

A day after a US Navy fighter jet shot down a Syrian warplane, Russia warned that aircraft operating where the shootdown occurred would be considered “air targets” for its forces in Syria.

The Russian Ministry of Defense called the downing of the plane “a cynical violation of the sovereignty of the Syrian Arab Republic” and “military aggression.”

As a result, it said, Russia has stopped using a key “de-confliction” communication channel set up to avoid conflict between US and Russian forces in Syria.

While both the US and Russia say their forces are in Syria to fight ISIS infiltration there, Russia has allied itself with the regime of Syrian President Bahsar al-Assad while the US-led coalition has aligned with groups that oppose both the Assad regime and ISIS.

Russian Deputy Foreign Minister Sergei Ryabkov said Monday the US shootdown of the Syrian Su-22 was “an act of assistance to those terrorists whom the United States is ostensibly fighting against,” according to Russia’s state-run news agency Tass.

02:05 - Source: CNN
Russia condemns US downing of Syrian warplane

The Syrian military acknowledged the loss of its aircraft and said the pilot was missing after ejecting.

It’s the first time the US has shot down a Syrian aircraft since it began fighting ISIS in the country in 2014.

“This strike can be regarded as another act of defiance of international law by the United States,” Ryabkov said.

Russia: Aircraft west of Euphrates River are ‘targets’

The Russian Defense Ministry said it would exert new control over the skies of western Syria.

“From now on, in areas where Russian aviation performs combat missions in the skies of Syria, any airborne objects found west of the Euphrates River, including aircraft and unmanned vehicles belonging to the international coalition, tracked by means of Russian land and air anti-aircraft defense, will be considered air targets,” the Defense Ministry statement reads.

Coalition forces released a response within hours of the Kremlin statements.

“As a result of recent encounters involving pro Syrian regime and Russian forces, we have taken prudent measures to reposition aircraft over Syria so as to continue targeting ISIS forces while ensuring the safety of our aircrews given known threats in the battle space,” coalition spokesman Col. Ryan Dillon told CNN.

“We are continuing to conduct operations throughout Syria targeting ISIS forces and providing air support for coalition forces and our partner forces on the ground,” Dillon said. “We as a coalition are always ready to deconflict.”

An escalated threat

A defense official told CNN the belief is the potential threat has escalated given recent encounters with pro-regime forces near At Tanf, as well as the downing of the Syrian aircraft.

In Washington, the chairman of the Joint Chiefs of Staff, Gen. Joseph Dunford, said communication between Russia and the US remains open.

03:15 - Source: CNN
Rep. Kinzinger talks Syrian conflict

Dunford said the US is working “diplomatically and militarily to reestablish a “de-confliction” channel.

“I am also confident that our forces have the capability to take care of themselves,” Dunford added. “The worst thing any of us can do right now is to address this thing with hyperbole.”

This is not the first time that Russia has said the “de-confliction” channel has been suspended. In April, after the US missile strike on a Syrian airbase, Russian Foreign Ministry spokeswoman Maria Zakharova said Russia would suspend the 2015 agreement aimed at minimizing risks of in-flight incidents.

The US military is prohibited by law from coordinating directly with the Russian military, but given the increased pace and scale of military operations in Syria, the US and Russia have sought ways to ensure that their respective personnel are not targeted by mistake, setting up a series of so-called “de-confliction zones” that delineate areas of operation for the coalition and the Russian forces.

03:06 - Source: CNN
Iran fires missiles into Syria

Analysts see positioning

With ISIS now significantly weakened, analysts believe all all parties in Syria are maneuvering to consolidate their positions for an eventual settlement of the conflict.

Jeremy Binnie, Middle East and Africa editor for Jane’s Defence Weekly, says the players in Syria are now operating with “half an eye on the post-Islamic State situation,” and looking to control as much territory as possible.

Related: Explaining the complex crisis in Syria

Russia could work to de-escalate the situation, but Moscow is “looking increasingly less like an honest mediator between the sides,” he says. “We don’t know until we see how it plays out in reality, but it is definitely Russia making a pretty strong statement in favor of the Assad government.”

Dmitry Trenin, director of the Carnegie Moscow Center, says the events of Sunday and Monday are a significant escalation, which could result in a “collision” between the two sides. To defuse the situation, he said, the US needs to begin to see Russia as a more equal partner in determining the future of Syria.

“It is time for diplomacy,” he said.

CNN’s Mary Ilyushina, Barbara Starr, Jill Dougherty and Emma Burrows contributed to this report.