President Trump criticized Attorney General Jeff Sessions on Twitter Saturday morning. The president has expressed frustration with Sessions multiple times this week as former allies have become embroiled in investigations.

"Jeff Sessions said he wouldn't allow politics to influence him only because he doesn't understand what is happening underneath his command position," Mr. Trump tweeted on Saturday.

The tweet follows a week in which former Trump campaign chairman Paul Manafort was found guilty of eight financial crimes, the first trial victory by prosecutors in special counsel Robert Mueller's investigation into Mr. Trump's associates. On the same day, former Trump lawyer and fixer Michael Cohen pleaded guilty to eight counts including two campaign finance violations involving payments to silence women.

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In his tweet, Mr Trump said, "Highly conflicted Bob Mueller and his gang of 17 Angry Dems are having a field day as real corruption goes untouched. No Collusion!" (Thirteen of the 17 staff attorneys on Mueller's team have previously been registered as Democrats, although Mueller himself is a Republican.)

Jeff Sessions said he wouldn’t allow politics to influence him only because he doesn’t understand what is happening underneath his command position. Highly conflicted Bob Mueller and his gang of 17 Angry Dems are having a field day as real corruption goes untouched. No Collusion! — Donald J. Trump (@realDonaldTrump) August 25, 2018

In regard to Sessions, Mr. Trump appeared to be referring to a statement Sessions released on Thursday in which he said he would "not be improperly influenced by political considerations." That was a response to Mr. Trump's interview with "Fox & Friends" Thursday morning in which Mr. Trump said Sessions never "took control" of the Justice Department.

The president's frustration with his attorney general stems from Sessions' recusal from the Russia investigation, which led to Deputy Attorney General Rod Rosenstein's appointment of special counsel Robert Mueller last year.

"I put an attorney general in that never took control of the Justice Department, Jeff Sessions, never took control of the Justice Department and it's sort of an incredible thing," Mr. Trump told "Fox & Friends" Thursday.

In his statement responding to the interview, Sessions said Thursday, "I took control of the Department of Justice the day I was sworn in, which is why we have had unprecedented success at effectuating the president's agenda—one that protects the safety and security and rights of the American people, reduces violent crime, enforces our immigration laws, promotes economic growth, and advances religious liberty."

Mr. Trump again tweeted his frustration with Sessions Friday.

"Jeff, this is GREAT, what everyone wants, so look into all of the corruption on the "other side,"" Mr. Trump said in response to Sessions' statement. "Come on Jeff, you can do it, the country is waiting!"

“Department of Justice will not be improperly influenced by political considerations.” Jeff, this is GREAT, what everyone wants, so look into all of the corruption on the “other side” including deleted Emails, Comey lies & leaks, Mueller conflicts, McCabe, Strzok, Page, Ohr...... — Donald J. Trump (@realDonaldTrump) August 24, 2018

....FISA abuse, Christopher Steele & his phony and corrupt Dossier, the Clinton Foundation, illegal surveillance of Trump Campaign, Russian collusion by Dems - and so much more. Open up the papers & documents without redaction? Come on Jeff, you can do it, the country is waiting! — Donald J. Trump (@realDonaldTrump) August 24, 2018

Mr. Trump also tweeted on Saturday about Hillary Clinton and the FBI.

"Big story out that the FBI ignored tens of thousands of Crooked Hillary Emails, many of which are REALLY BAD. Also gave false election info. I feel sure that we will soon be getting to the bottom of all of this corruption. At some point I may have to get involved!" Mr. Trump tweeted.

Big story out that the FBI ignored tens of thousands of Crooked Hillary Emails, many of which are REALLY BAD. Also gave false election info. I feel sure that we will soon be getting to the bottom of all of this corruption. At some point I may have to get involved! — Donald J. Trump (@realDonaldTrump) August 25, 2018