Michael McFaul says that American diplomats have been working with Russian diplomats since Max Shatto was pronounced dead in late January.
However, McFaul also said that the death is still under investigation.
McFaul added that Russia needs to stop this "senseless exploitation of human tragedy."
Max Shatto, 3, died in January in Gardendale.
Ector County Sheriff's deputies are waiting for autopsy results to come back to determine the cause of Shatto's death.