What the White House has said about special prosecutors

— -- News that the Department of Justice appointed a special counsel, former FBI Director Robert Mueller, to lead the Russia probe rocked Washington.

Many who had been asking for an independent voice in the matter applauded the move and Trump himself reportedly had a measured reaction at first.

But Thursday morning, Trump lashed out on Twitter, calling it the "single greatest witch hunt of a politician in American history!"

Later in the day, he told ABC News' David Muir it "hurts our country terribly" while at a press conference with the Colombian president, he said "I respect the move."

Here's a look back at what the administration has said about special counsel (often referred to as special prosecutors), from the Russia investigation to Hillary Clinton:

Earlier this week, during the daily press briefing on May 15, White House Press Secretary Sean Spicer said a special prosecutor wasn't needed to look into the Russia investigation.

"There’s, frankly, no need for a special prosecutor. We’ve discussed this before," Spicer said. "You have two Senate committees that are looking into this. The FBI is conducting their own review. And I think if you even look at what Acting Director [Andrew] McCabe said last week, he made it very clear that they had the resources that they need and that the work continues."

"It’s been made very clear that there’s been, with respect to the President himself, both Senator [Chuck] Schumer, Senator [Dianne] Feinstein, Senator [Joe] Manchin and everyone else who have been briefed on this, have been very clear that there was no collusion with respect to the President himself and no investigation there," he added.

Days earlier, on May 10, Deputy Press Secretary Sarah Huckabee Sanders told reporters "we don't think it's necessary" to appoint a special prosecutor.

"You've got the deputy attorney general, who I would say is about as independent as it comes, due to the fact that he has such bipartisan support," she said, as well as "a House committee, a Senate committee and the Department of Justice all working on this."

"I don't think that there's a necessary need at this point to add that," Sanders said.

At the Feb. 27 press briefing, Spicer said, "I think that Russia's involvement in activity has been investigated up and down."

"I think that both the House and the Senate have looked at it. ... the intelligence community has looked at it, as well," Spicer said. "So the question becomes at some point, if there's nothing to further investigate, what are you asking people to investigate?"

"The President has spoken forcefully time and time again that he has no interests in Russia, he hasn’t talked to people in Russia in years, and yet you keep asking," Spicer said. "What do you need to further investigate if there is nothing that has come out?"

One day earlier, Sanders told ABC News chief anchor George Stephanopoulos on "This Week," "I don't think we're there yet" for potentially appointing a special prosecutor.

"Typically, you go through a congressional oversight review. We're doing that," she said. "Let's not go to the very end of the extreme. Let's let this play out the way it should."

Sanders said on "This Week" that Congress should complete its review first, which she said she is confident will show that Trump associates had not involvement in Russia's actions.

"Whatever review that Congress wants to do, I think that's the first step," she said. "There are two committees that are currently doing that. We're extremely confident that, whatever review, they're all going to come to the same conclusion -- that we had no involvement in this."

Sanders also suggested that a Russia probe is not something "that the American people care about."

"At some point, we get to a place where we've got to move on and start focusing on the things that the American people care about, and I don't think this is it," she said.

During the 2016 presidential campaign, Trump repeatedly vowed to instruct a special prosecutor to investigate Clinton if he won.

In August, Trump said to an enthusiastic crowd that a special prosecutor must take over the investigation into his Democratic rival's emails.

"After the FBI and Department of Justice whitewashed Hillary Clinton’s email crimes, they certainly cannot be trusted to quickly or impartially investigate Hillary Clinton’s new crimes," Trump said. "The Justice Department is required to appoint an independent Special Prosecutor because it has proven itself to be really, sadly a political arm of the White House.”

During the second presidential debate on Oct. 9, Trump said to Clinton, "I hate to say it but, if I win, I am going to instruct my Attorney General to get a special prosecutor to look into your situation. Because there has never been so many lies, so much deception. There has never been anything like it. And we’re going to have a special prosecutor.”