WASHINGTON -- Special counsel Robert Mueller said in a rare and remarkable public statement Wednesday that charging President Donald Trump was not an option his office could consider.
Mueller, speaking from the Justice Department, said he's closing the special counsel's office and returning to private life.
"If we had confidence the President clearly did not commit a crime, we would have said so," Mueller said.
Mueller also said that he does not intend to testify before Congress, as House Democrats have been pressing him to do. The special counsel said he decided himself against testifying, adding that any testimony would not go beyond the report.
"I hope and expect this will be the only time I will speak to you in this manner," he said.
"It's important the office's written work speaks for itself," Mueller said about his report, which was delivered in March to Attorney General William Barr.
After the statements, the President tweeted, "The case is closed!"
"There was insufficient evidence and therefore, in our Country, a person is innocent," Trump wrote.
The statement was delivered amid political disputes about the findings of Mueller's investigation, particularly regarding whether Trump obstructed justice.
The Justice Department released a redacted version of the special counsel's report last month. The report detailed numerous cases in which Trump asked his aides to take actions that would have obstructed the investigation, but stated they were unsuccessful because the aides refused his orders.
The report also says that the investigation into possible collusion found that members of the Trump campaign knew they would benefit from Russia's illegal actions to influence the election, but didn't take criminal steps to help.
Charging Trump was "not an option" because Justice Department regulations prohibit charging a sitting president with a crime, Mueller said. His office was "bound by that policy."
"It would be unfair to potentially accuse somebody of a crime when there can be no court resolution of an actual charge," he said.
Mueller highlighted how the "Constitution requires a process other than" the criminal justice system to hold officeholders accountable, a clear signal that his obstruction investigation into Trump may be picked up by Congress.
Mueller called the subject of his investigation "of paramount importance," and said that obstructing an investigation "strikes at the core of the government's effort to find the truth and hold wrongdoers accountable."
The White House got a heads up Tuesday night that Mueller would likely deliver a statement on Wednesday about the Mueller investigation, according to a senior administration official.
Barr also was given advance notice, according to a source familiar with the plans. House Judiciary Committee Chairman Jerry Nadler, D-New York, was also notified, a committee spokesman said.
Trump has claimed 'complete and total exoneration'
Trump, citing a letter from Barr to Congress about Mueller's conclusions, has said the investigation provided a "complete and total exoneration."
But Mueller's report only said the investigation "did not establish that members of the Trump campaign conspired or coordinated with the Russian government," and Mueller expressed concerns in a letter to Barr that the attorney general's letter summarizing his findings didn't fully capture his 448-page report, a source with knowledge of the letter has told CNN.
Trump has wavered publicly in recent weeks on the prospect of Mueller's testimony before Congress as his administration has clashed sharply with lawmakers over demands for documents and testimony.
Asked earlier in May, the President said, "I don't know. That's up to our attorney general, who I think has done a fantastic job."
Days later, Trump reversed course and said Mueller "should not testify" as the President resurfaced his regular complaints about the Mueller investigation, before switching back again and saying the decision would be up to "our very great attorney general."
Barr recently told The Wall Street Journal that he would not prevent Mueller from testifying before Congress.