WASHINGTON (AP) — A day after announcing the departure of his White House counsel, President Donald Trump teased Thursday that he has settled on a successor, tweeting that he's "very excited" about his choice, whose name he kept secret.

Trump announced Wednesday on Twitter that Don McGahn will leave in the fall. He has been a consequential insider on Trump's legal team and a key figure in the administration's handling of the special counsel investigation into Russian election interference and possible collusion with the Trump campaign.

"I am very excited about the person who will be taking the place of Don McGahn as White House Councel!," Trump tweeted Thursday, misspelling "counsel."

"I liked Don, but he was NOT responsible for me not firing Bob Mueller or Jeff Sessions. So much Fake Reporting and Fake News!" Trump said, referring to the special counsel overseeing the Russia investigation and the attorney general.

Trump also said the Russia investigation was not a factor, "even a little bit," in his decision about McGahn's departure.

McGahn's exit continues the churn of top officials as the administration sets records for turnover and the White House struggles to fill key vacancies.

Unlike some less-amiable separations, however, Trump praised McGahn as "a really good guy" who has done "an excellent job."

Trump said Wednesday that McGahn's departure had nothing to do with his interviews with the special counsel. Pressed by reporters, Trump said he had approved the interviews and was unconcerned about anything McGahn might tell prosecutors.

"We do everything straight," he said. "We do everything by the book."

The departure of Trump's top lawyer, which has been expected, will create a vacancy in one of the most critical — and yet least visible — positions within the West Wing. Besides dealing with Mueller's investigation, McGahn has had important input on a range of issues from policy to personnel to national security.

He will remain at the White House until after the expected Senate confirmation vote for Supreme Court nominee Brett Kavanaugh, Trump said in a tweet.

McGahn, a top election lawyer who served as general counsel on Trump's campaign, has played a pivotal role in the president's remaking of the federal judiciary with young, conservative judges.

He also helped guide Trump's selection of Supreme Court Justice Neil Gorsuch and the president's nomination of Kavanaugh and helped oversee a dramatic rollback of Obama-era regulations.

But McGahn's time has also been marked by tumult as he has been the main point of contact inside the White House for Mueller's investigation. He has met with investigators on at least three occasions for many hours at a time and threatened to resign last year if Trump continued to press for Mueller's removal.

Trump's announcement came more than a week after a New York Times report that McGahn had been cooperating extensively with Mueller's investigation into Russian election meddling and possible collusion with Trump's Republican campaign.

Trump insisted at the time that his general counsel wasn't a "RAT" and contrasted him with John Dean, the White House counsel for President Richard Nixon during the Watergate scandal. Dean ultimately cooperated with prosecutors and helped bring down the Nixon presidency in 1974, though he served a prison term for obstruction of justice.

McGahn has been telling associates for months that he was looking to leave the White House and had discussed the timing. But Trump's tweet came as a surprise to some White House officials and lawmakers.

In fact, Sen. Chuck Grassley, R-Iowa, the chairman of the Senate Judiciary Committee, tweeted after the president's announcement: "I hope it's not true McGahn is leaving White House Counsel. U can't let that happen."

Senate Majority Leader Mitch McConnell hailed McGahn as the "most impressive White House Counsel during my time in Washington." He called the departure "sad news for our country."

Emmet Flood, who joined Trump's White House in May as in-house counsel for the Mueller probe, has been considered a leading candidate to replace McGahn and has the departing attorney's support, two administration officials said. They spoke on the condition of anonymity to discuss personnel matters.

Asked about Flood on Wednesday, White House press secretary Sarah Huckabee Sanders said: "People like him. He's super well-respected around the building. But there's not a plan locked in place at this point."