In a series of tweets, Trump accused Mueller of causing "tremendous" damage to the nation's criminal justice system and “only looking at one side” in his investigation.
The president in the tweets referenced the FBI's shuttered investigation into Hillary Clinton, which chastised her for being "extremely careless" in her use of a private email server to do official business during her time as secretary of State.
Trump for more than a year has denounced Mueller's investigation as a "hoax" and a "witch hunt," insisting there was "no collusion" between his campaign and Russia. He has sometimes deflected by accusing Clinton of collusion with Moscow.
The president recently submitted his written answers to some of Mueller's questions, but his legal team says Trump did not provide answers for Mueller's probe into the possibility that Trump sought to obstruct the Russia investigation.