Trump decries 'witch hunt' after special counsel appointed in Russia investigation Former FBI chief Robert Mueller will lead the new Russia investigation.

 -- President Donald Trump is responding to the appointment of a special counsel to investigate Russia's interference in the 2016 presidential election, calling the Russia probe the "single greatest witch hunt of a politician in American history!"

Trump also suggested Hillary Clinton's presidential campaign and the Obama administration committed "illegal acts" and "there was never a special counsel appointed!"

It was announced Wednesday that former FBI Director Robert Mueller was appointed as a special counsel to oversee the investigation into Russia's meddling in last year's election and any possible ties between Trump campaign associates and Russia.

The appointment of a special counsel comes during a tumultuous period for the White House, after the sudden firing of FBI Director James Comey and reports of a memo written by Comey detailing a request allegedly by Trump to drop an investigation into former national security adviser Mike Flynn.

The special counsel announcement was made by Deputy Attorney General Rod Rosenstein, who the White House initially said made the initial recommendation to fire Comey. Attorney General Jeff Sessions has recused himself from any existing or future investigations related to Russia.

The White House had "absolutely no indication" the appointment was coming and was given a heads-up less than an hour before it was publicly announced, according to a senior White House official.

In a statement released Wednesday night, Trump shot down allegations that his campaign had ties to "any foreign entity" and said that he looks forward to "this matter concluding quickly."

"As I have stated many times, a thorough investigation will confirm what we already know — there was no collusion between my campaign and any foreign entity," the statement read.