US Special Counsel Robert Mueller, in his first public comments on his Russia interference investigation, said on Wednesday that charging President Donald Trump was never an option for his team of prosecutors, citing Justice Department guidelines that prohibit charging a sitting president.
"Charging the president with a crime was ... not an option we could consider," Mueller told reporters as he announced his resignation.
"We concluded that we would not reach a determination one way or the other about whether the president committed a crime."
He indicated it was up to Congress to decide if impeachment proceedings are justified.
"The Constitution requires a process other than the criminal justice system to formally accuse a sitting President of wrongdoing," Mueller said as he announced his resignation from the Justice Department.
Democrats in Congress are debating whether to try to move ahead with impeachment, an effort that is almost certain to fall short in the Republican-controlled Senate.
The White House and several top Republicans said it was time to move on to other matters, while several Democratic presidential candidates called for impeachment.
“What Robert Mueller basically did was return an impeachment referral,” Senator Kamala Harris said on Twitter.
“Given that Special Counsel Mueller was unable to pursue criminal charges against the President, it falls to Congress to respond to the crimes, lies and other wrongdoing of President Trump – and we will do so,” said Jerrold Nadler, the Democratic chairman of the House of Representatives Judiciary Committee.
A redacted version of Mueller’s report was published in April, concluding that Russia repeatedly interfered in the 2016 election and that Trump’s election campaign had multiple contacts with Russian officials, but did not establish a criminal conspiracy with Moscow to win the White House.
Mueller’s report also declined to make a judgment on whether Trump obstructed justice, although the report outlined 10 instances in which Trump tried to impede the investigation, including seeking to have Mueller fired.
“If we had confidence that the president clearly did not commit a crime, we would have said so,” Mueller said. “We did not, however, make a determination as to whether the president did commit a crime.”