In this file photo taken on August 1, 2013, former Federal Bureau of Investigation (FBI) Director Robert Mueller speaks during a farewell ceremony in his honor at the Department of Justice. Image Credit: AFP

WASHINGTON: Special Counsel Robert Mueller said Wednesday that charging US President Donald Trump with a crime of obstruction was not an option because of Justice Department policy.

"A Special Counsel's Office is part of the Department of Justice, and by regulation, it was bound by that department policy," Mueller said in his first public comments in two years.

"Charging the president with a crime was therefore not an option we could consider," the former FBI director said.

At the same time, Mueller reiterated that his report into Russian interference in the 2016 election did not exonerate the president.

"If we had 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."