U.S. Secretary of State Rex Tillerson says he was "disappointed" but "not surprised" by Russia's angry reaction to this week's U.S. missile strikes in Syria.
Moscow denounced the barrage of missile strikes on a Syrian air base on April 7 as an "act of aggression" and violation of international law, and said it would suspend lines of communication with the U.S. military in Syria and help Syria increase its air defenses against future attacks.
"I'm disappointed in that response from the Russians because it indicates their continued support...for a regime that carries out these kinds of horrendous attacks on their own people." said Tillerson, who will travel to Moscow for his first official visit next week.
"I find it very disappointing, but sadly, I have to tell you, not all that surprising," he said.
U.S. President Donald Trump said the attack was intended to punish Syria for its use of chemical weapons against civilians in a deadly incident this week.
The Pentagon said the Shayrat air base, which was partially destroyed by the attack, was the one used by Syria's air force to launch a nerve-gas attack on the town of Khan Sheikhoun on April 4, killing at least 86 people.
On April 8, Iranian President Hassan Rohani called for an impartial probe into the alleged chemical attack in Syria.
"We are asking for an impartial international fact-finding body to be set up...to find out where these chemical weapons came from," Rohani said as he condemned the U.S. missile strikes as an "aggression."
Tehran is Syrian President Bashar al-Assad's main regional ally.