US PRESIDENT Donald Trump has said that White House counsel Don McGahn would soon be leaving his post, as Special Counsel Robert Mueller — who is leading the Russia election interference probe — closes in on the US president’s inner circle.

Mr Trump made the announcement on Twitter.

“I have worked with Don for a long time and truly appreciate his service!” he added, without offering any reason why Mr McGahn was leaving.

Earlier this month, The New York Times reported that Mr McGahn had “co-operated extensively” with Mr Mueller’s team, taking part in at least three interviews with investigators totalling 30 hours.

Mr Trump said he had authorised his team to co-operate with investigators, but speculation rose about what Mr McGahn might have specifically said about whether the Republican leader sought to obstruct justice.

McGahn, a top election lawyer who served as general counsel on Mr 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 Mr Kavanaugh and helped oversee a dramatic rollback of Obama-era regulations.

The White House counsel is among the most critical — and yet least visible — positions within the West Wing, with input on a range of issues from policy to personnel to national security.

But Mr McGahn’s time has also been marked by tumult as the main point of contact inside the White House for the Russia investigation led by special counsel Robert Mueller.

Mr McGahn, who has consented to interviews with Mr Mueller’s team, threatened to resign last year if Mr Trump continued to press for Mr Mueller’s removal.

Mr McGahn’s impending departure is raising concerns within Congress.

Republican Senator Charles Grassley, 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.”

Emmet Flood, who joined Mr Trump’s White House in May as in-house counsel for the Mueller probe, has been considered a leading candidate to replace Mr McGahn.

Asked about Mr Flood, 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.”