The US is “disappointed but not surprised” at Russia’s response to its strikes on a Syrian air base, BBC reported.
Syria’s ally Russia accused the US of encouraging terrorism and lawlessness.
“I’m disappointed in that response,” said US Secretary of State Rex Tillerson.
“It indicates their continued support for the Assad regime and, in particular, their continued support for a regime that carries out these type of horrendous attacks on their own people.
“So I find it very disappointing, but, sadly, I have to tell you, not all that surprising,” he added.
In this aspect, Moscow has promised to strengthen Syria’s anti-aircraft defences.