"I declined to answer the questions under the rights and privileges afforded to every citizen under the United States Constitution," Trump said in a statement, referring to the Fifth Amendment right against self-incrimination.

"I once asked, 'If you're innocent, why are you taking the Fifth Amendment?'" Trump said. "Now I know the answer to that question. When your family, your company, and all the people in your orbit have become the targets of an unfounded, politically motivated Witch Hunt supported by lawyers, prosecutors, and the Fake News Media, you have no choice."

Trump wrote that the FBI's Monday raid of his Mar-a-Lago resort in Palm Beach, Fla. — reportedly a search for presidential records that may contain classified information —  "wiped out any uncertainty" about whether to cooperate.