The special counsel investigating potential ties between Donald Trump's presidential campaign and Russia has obtained a draft of a letter that explains reasons why Trump planned to fire former FBI Director James Comey, The New York Times reported Friday.

The Justice Department turned over a copy of the letter, which was drafted by Trump and top aide Stephen Miller, to Mueller in recent weeks, the Times reported, citing interviews with a dozen administration officials and others briefed on the matter.

The Times report doesn't say what was in the letter, which was originally meant to be sent directly to Comey, according to the Times. Ty Cobb, a White House lawyer, declined to discuss the letter or its contents to the Times.

But it was met with opposition from White House counsel Don McGahn, who saw its contents as "problematic," the Times reported.

Instead, a letter written by Deputy Attorney General Rod Rosenstein that was focused on criticizing Comey's handling of the investigation into Hillary Clinton's private email server was cited behind Trump's decision to fire the FBI chief.

After Comey was fired in May, Trump has said he was thinking of "this Russia thing" when he decided to fire Comey, who had been leading the bureau's investigation into alleged Russian meddling in the 2016 election.

Trump told NBC News in May that he was frustrated by the ongoing investigation and believes it was motivated by Democrats' fury at losing the election.

With those comments, Trump explicitly tied the Russia probe to his rationale for firing Comey. It was one of a series of explanations for dismissing the FBI director, some of which directly contradict those offered earlier by top White House officials.

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