President Donald Trump in the Oval Office of the White House on Tuesday. AP Photo/Evan Vucci President Donald Trump has hit back against the Justice Department's appointment of a special counsel.

"With all of the illegal acts that took place in the Clinton campaign & Obama Administration, there was never a special councel appointed!" Trump said on Twitter on Thursday morning.

"This is the single greatest witch hunt of a politician in American history!" Trump continued.

The Justice Department on Wednesday appointed former FBI Director Robert Mueller to oversee investigations into potential ties between Trump associates and Russian operatives.

"My decision is not a finding that crimes have been committed or that any prosecution is warranted," Deputy Attorney General Rod Rosenstein said in a statement announcing he had appointed Mueller to the role. "I have made no such determination. What I have determined is that based upon the unique circumstances, the public interest requires me to place this investigation under the authority of a person who exercises a degree of independence from the normal chain of command."

The president's tweets followed a "Fox & Friends" segment Thursday that made a similar argument: