"Commencing Saturday, August 31, the US State Department repeatedly requested phone call with (Russian foreign minister) Sergei Lavrov. Although we have constantly confirmed it, the US side every time informed us there was no possibility to get through to the secretary of state," ministry spokesperson Alexander Lukashevich said.
He added that Russian attempts to set up an exact time for a phone conversation with John Kerry have also been left unanswered.
In a separate statement, the foreign ministry said that US intentions to carry out a military strike against Syria would contradict the core of international law.
"Response of the international community and separate states on chemical weapons use must fit the strict legal frames. Any reaction must be backed by the results of a thorough independent investigation," it said.
Moscow said if Damascus actually used chemical weapons, it could be qualified as violation of the international law.