Trump renews criticism of Sessions over Mueller investigation

President Donald Trump is again criticizing the FBI's investigation into Hillary Clinton's emails and he's suggesting that "at some point" he "may have to get involved!"

Trump is asserting, without providing evidence, that the FBI failed to thoroughly review Clinton's emails as part of its investigation into her use of a private email server while she served as secretary of state.

The president also tweets more criticism of Attorney General Jeff Sessions, writing that Sessions "doesn't understand what is happening underneath his command position."

In a rare rebuttal to Trump, Sessions said on Thursday that he "took control of the Department of Justice" the day he became attorney general, and that "the actions of the Department of Justice will not be improperly influenced by political considerations."

In a tweet on Saturday morning, Trump replied that Sessions "doesn't understand what is happening underneath his command position."

Special Counsel Robert Mueller, who is running the Russia probe, is "highly conflicted" and "real corruption goes untouched," Trump continued.

Sessions, a former U.S. senator from Alabama, was one of the first Republican lawmakers to back Trump's presidential election bid and has implemented his hardline immigration policies in the role of attorney general.

But Trump has repeatedly criticized Sessions for recusing himself from the Russia probe, including in a Fox News interview taped on Wednesday when he said that Sessions "never took control of the Justice Department."

Trump denies any collusion with Moscow and calls the investigation a "witch hunt."

The back-and-forth between Trump and Sessions has sparked new speculation that Trump might fire Sessions.