Azerbaijan’s leader on Monday accused Moscow of carrying out a “cover up” over a passenger jet crash last month that claimed 38 lives, as relations sour between the two neighbors.

Russian President Vladimir Putin apologized for the “tragic incident,” which left 38 people dead, though he stopped short of taking responsibility.

Azerbaijan President Ilham Aliyev said Russia is behind the Christmas Day crash of an Azerbaijan Airlines plane in Kazakhstan, which killed 38 of the 67 people aboard. The motives of the incident remain unclear.

"Unfortunately, in the first three days we heard only absurd versions from Russia," President Ilham Aliyev said, citing statements in Russia that attributed the crash to a bird strike or the explosion of some sort of gas cylinder.

Azerbaijani leader Ilham Aliyev is demanding answers, saying Vladimir Putin's latest apology "isn't enough" and that Moscow must take responsibility.

Azerbaijan's president has confronted Putin over the devastating plane crash that killed 38 people on Christmas Day.

We demand justice, we demand punishment for those responsible, and we demand full transparency, — said the President of Azerbaijan, Ilham Aliyev, regarding the plane crash caused by a Russian missile.