Russia reacted strongly to the US air strike on a Syrian airbase, saying it would impair the already "deplorable" bilateral relations and hamper the "effective fight" against terrorism.
Russian Presidential Spokesman Dmitry Peskov, citing the opinion of Russian President Vladimir Putin, termed the air strike as an act of "aggression" against a sovereign state, TASS news agency reported.
Peskov also said that Putin considered the strike "an attempt to distract attention from numerous civilian casualties in Iraq".
"Washington's move impairs the Russian-US relations, which are in a deplorable state, substantially," Peskov said.
The strike on Thursday night targeted the Shairat military base in Homs province that left four Syrian soldiers dead, a monitor group said.
The US fired 59 Tomahawk missiles, causing huge damages to the airbase, Homs Governor Talal Barazi said.
"Putin believes that this step does not bring us closer to the ultimate goal in the fight against international terrorism... It creates serious obstacles to efforts to forge an international coalition to fight against it and effectively counter this global evil," the Kremlin spokesman said.
According to the US, the strike was in response to the Syrian government's chemical weapons attack that killed dozens of civilians in Khan Sheikhoun area of Idlib province.