Riad Haddad, Syria's envoy to its ally Russia, told the state TV channel Rossiya 24 that the hospital in Idlib had been hit earlier in a US raid.
"American warplanes destroyed it. Russian warplanes had nothing to do with any of it -- the information that has been gathered will completely back that up," Haddad said.
The United Nations said earlier that air strikes on at least five medical facilities and two schools in northern Syria's Aleppo and Idlib provinces, northwest Syria, killed nearly 50 civilians including children.
It said such action "casts doubt on Russia's willingness and/or ability to help bring to a stop the continued brutality of the Assad regime against its own people".
Haddad said US accusations "are a sign of the war of propaganda, which began in the very first days of the conflict in Syria.