President Trump believes that the appointment of a special counsel "hurts our country terribly," he said Thursday, a day after a special counsel was appointed to oversee the FBI investigation into Russian efforts to influence the 2016 presidential election, including any ties between Russia and Mr. Trump's campaign.

Asked about the appointment at a lunch with television network anchors, the president said, "I believe it hurts our country terribly, because it shows we're a divided, mixed-up, not-unified country. And we have very important things to be doing right now, whether it's trade deals, whether it's military, whether it's stopping nuclear -- all of the things that we discussed today. And I think this shows a very divided country."

On Wednesday, Deputy Attorney General Rod Rosenstein appointed former FBI Director Robert Mueller to be the special counsel. Mueller, who is well-regarded by both parties, was a name welcomed by Democrats and by some Republicans, as well.

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That did not appear to make a difference to Mr. Trump, who reiterated that he thinks the investigation is "a pure excuse for the Democrats having lost an election that they should have easily won because of the Electoral College being slanted so much in their way. That's all this is."

Mr. Trump said he thinks "it's a very, very negative thing. And hopefully, this can go quickly, because we have to show unity if we're going to do great things with respect to the rest of the world."

The president also made his ire known over Twitter, earlier Thursday.

This is the single greatest witch hunt of a politician in American history! — Donald J. Trump (@realDonaldTrump) May 18, 2017