WASHINGTON - Matthew Whitaker, acting US attorney general, said Friday that he has not interfered with the ongoing Russia investigation led by special counsel Robert Mueller.

"There has been no event, no decision that has required me to take any action," Whitaker told the House Judiciary Committee Friday morning. "I have not interfered in any way with the special counsel's investigation."

He also confirmed he has been briefed on the wide-ranging inquiry but refused to talk in details, only insisting that he has not talked to President Donald Trump or senior White House officials about it.

Whitaker is directly overseeing the Mueller-led investigation, which has focused on possible collusion between the Trump campaign and Moscow during the 2016 US presidential elections and whether the president obstructed justice, among other things.

Seen as a close ally to Trump, Whitaker has been questioned over his past criticism of the Russia probe and his refusal to step aside despite advice from the Justice Department's ethics officials.

Trump tabbed Whitaker to lead the agency on a temporary basis after former Attorney General Jeff Sessions was ousted immediately after the midterm elections in November.

The Democrat-led House panel was holding the hearing over Whitaker's oversight of the probe, his contacts with White House related to it and the firing of Sessions.

"Mr. Whitaker, like everyone else at the Department of Justice, you are entitled to your political opinions," House Judiciary Committee Chairman Jerry Nadler said at Friday's hearing.

"But when career officials at the department recommended that you take steps to mitigate your apparent conflicts of interest, Mr. Whitaker -- when they told you that your public criticism of the special counsel was bad for the department and bad for the administration of justice, you ignored them," the New York Democrat added.

Whitaker defended by saying, "We have followed the special counsel's regulations to a T."

The hearing was thrown into uncertainty after Democrats threatened to subpoena Whitaker, who had previously agreed to testify.

The acting attorney general warned that he wouldn't show up unless lawmakers dropped the ultimatum he described as "political theater," before reaching an agreement with Nadler Thursday to allow the hearing to occur as planned.

Doug Collins, the top Republican on the House Judiciary Committee said Friday the hearing with Whitaker is a "dog and pony show."

The Georgia Republican added the hearing was pointless because the nomination of William Barr, Trump's official pick for attorney general, is expected to be confirmed in a vote that could come as early as next week.

Collins ended his remarks with a motion to adjourn the hearing. That motion was later defeated.

Whitaker said late last month that Mueller's investigation is "close to being completed," although there has been no confirmation of this from the special counsel's office.

Trump has repeatedly blasted inquiry and said there was "no collusion" between his campaign and Russia. Moscow has denied any meddling in the 2016 presidential election.