(CNN) President Donald Trump on Tuesday submitted written answers to questions from special counsel Robert Mueller related to the investigation of possible collusion between Trump associates and Russians.

The responses from the President signify a major development in the Mueller probe following months of negotiations between the special counsel's office and Trump's legal team, and could be a sign of the end stages of the investigation.

Trump told reporters before boarding Marine One to travel to Mar-a-Lago in Florida that he finished the written answers on Monday and provided them to his lawyers. "The written answers are finished," Trump said. "The written answers to the witch hunt that's been going on forever."

Asked whether he thought Mueller would be fair, Trump said he hopes so.

"The President today answered written questions submitted by the special counsel's office," Trump attorney Jay Sekulow said in a statement. "The questions presented dealt with issues regarding the Russia-related topics of the inquiry. The President responded in writing."

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