Russia won't say if it mistakenly downed an Azerbaijani plane on Christmas. But it acknowledges the crash came amid a Ukrainian drone attack in its republic of Chechnya.

"No one claims that it was done on purpose," an Azerbaijan official told Reuters. They added their government "expects the Russian side to confess."

Two U.S. military officials tell NBC News the U.S. has intelligence indicating that the Russians may have misidentified the Azerbaijan Airlines flight that went down earlier this week, and shot it down with an air defense system.

Azerbaijan Airlines says the jet that crashed in Kazakhstan on Christmas Day experienced “physical and technical external interference,” according to an early investigation, as questions swirled about Russia’s possible involvement in the disaster.

Experts say evidence in the Azerbaijan Airlines plane crash in Kazakhstan points to a possible midair explosion, not an encounter with a flock of birds.