Russia has threatened to treat United States coalition aircraft as targets in Syria, according to The Washington Post.

Russia condemned the U.S. latest strike against a Syrian aircraft, calling it a “flagrant violation of international law.” Russia said it will now treat any aircraft or drones as threats if they operate in any areas west of Euphrates.

Russian defense ministry said it will suspend an agreement between the U.S. and Russia that worked to limit the risk of in-flight incidents between the two countries, The Washington Post reported.

Russia’s decision came after the U.S. confirmed it shot down a Syrian Su-22 fighter bomber Sunday.

Russian Defense Ministry said its own warplanes had been in the same space as the Syrian-U.S. strike, according to The Washington Post.

“Multiple military actions of U.S. aviation under the guise of fighting terrorism against the legal military of a state that is a member of the United Nations are a flagrant violation of international law and constitute de facto military aggression against the Syrian Arab Republic,” the ministry said, according to The Washington Post. “We view these actions by the American command as a conscious failure to uphold their responsibilities within the memorandum,” the ministry said.

Frants Klintsevich, the deputy chairman of the Russian Senate’s defense committee, said the attack was a “blunt act of aggression and provocation.”

Klintsevich wrote on Facebook that Russia was provoked because of the attack.

“It is Russia that is being provoked most of all,” Klintsevich wrote. “It seems that the U.S. under Donald Trump is the source of danger for the Middle East and the whole world on a qualitatively new level.”