3:54 P.M. UPDATE:
President Donald Trump has responded with a direct "no, no" to a question about whether he asked former FBI Director James Comey to shelf an investigation into his former national security adviser.
Trump also was questioned Thursday over revelations that he had shared secrets with the Russians. He denied that as well.
Comey associates this week revealed the existence of a memo Comey wrote after his Feb. 14 meeting with Trump in which he says the president asked him to shut down the FBI investigation into ousted National Security Adviser Michael Flynn.
Trump sent Comey a letter last week abruptly firing him.
Read Friday's Arkansas Democrat-Gazette for full details.
EARLIER:
WASHINGTON — President Donald Trump lashed out at the appointment of a special counsel to investigate allegations that his campaign collaborated with Russia to sway the 2016 election, tweeting Thursday that it is "the single greatest witch hunt of a politician in American history!"
The Justice Department on Wednesday appointed former FBI Director Robert Mueller to lead the investigation. Mueller will have sweeping powers and the authority to prosecute any crimes he uncovers.
The surprise announcement to hand the probe over to Mueller, a lawman with deep bipartisan respect, was a striking shift for Trump's Justice Department, which had resisted increasingly loud calls from Democrats for an outside prosecutor. It immediately escalated the legal stakes — and the potential political damage — for a president who has tried to dismiss the matter as partisan witch hunt and a "hoax."
In another Twitter post Thursday, Trump said: "With all of the illegal acts that took place in the Clinton campaign & Obama Administration, there was never a special councel (sic) appointed!" He did not provide examples or evidence of any alleged "illegal acts."
The announcement, the latest in the shock-a-day Washington saga, was made by deputy Attorney General Rod Rosenstein. The White House counsel's office was alerted only after the order appointing Mueller was signed, said a senior White House official, who was not authorized to speak publicly by name and commented only on condition of anonymity.
In a written statement, Trump insisted anew there were no nefarious ties between his campaign and Russia.
"A thorough investigation will confirm what we already know — there was no collusion between my campaign and any foreign entity," he declared. "I look forward to this matter concluding quickly."
Mueller's broad mandate gives him not only oversight of the Russia probe, but also "any matters that arose or may arise directly from the investigation." That would surely include Trump's firing last week of FBI Director James Comey.
Mueller, a former federal prosecutor at the Justice Department, was confirmed as FBI director days before the Sept. 11, 2001, attacks that would ultimately shape his tenure. The FBI's counterterror mission was elevated in those years, as the U.S. intelligence agencies adjusted to better position America to prevent another attack of such magnitude. He was so valued that President Barack Obama asked him to stay on two years longer than his 10-year term.
Comey succeeded him, appointed by Obama.