The Justice Department on Wednesday appointed former FBI Director Robert Mueller as a special counsel to oversee a federal investigation into potential coordination between Russia and Donald Trump's campaign during the 2016 presidential election. The appointment gives Mueller, who led the FBI through the Sept. 11 terrorist attacks and served under presidential administrations of both parties, sweeping powers to investigate whether Trump campaign associates colluded with the Kremlin to influence the outcome in his behalf, as well as the authority to prosecute any crimes uncovered during the probe. In a statement Mueller said, “I accept this responsibility and will discharge it to the best of my ability.” President Donald J. Trump sent a statement after the order was made public saying, "As I have stated many times, a thorough investigation will confirm what we already know – there was no collusion between my campaign and any foreign entity. I look forward to this matter concluding quickly. In the meantime, I will never stop fighting for the people and the issues that matter most to the future of our country." The broad mandate, beyond any specific Trump-Russia connection, also covers "any matters that arose or may arise directly from the investigation" - suggesting Mueller could explore the circumstances of the firing last week of FBI Director James Comey as well as a memo that Comey drafted to chronicle a February conversation with the president. Deputy Attorney General Rod Rosenstein, facing scathing criticism for authoring a memo that preceded the firing last week of James Comey as FBI Director, said in a statement that Mueller's appointment was "necessary in order for the American people to have full confidence in the outcome." "What I have determined is that based upon the unique circumstances, the public interest requires me to place this investigation into the authority of a person who exercises a degree of independence from the normal chain of command," Rosenstein said in a statement. The appointment came amid a growing Democratic outcry for someone outside the Justice Department to handle the politically charged investigation. It followed the revelation Tuesday that fired FBI Director James Comey had written in a memo that Trump, in a February meeting in the Oval Office, had asked him to end an investigation into former national security adviser Michael Flynn. The White House has denied that account. Mueller was appointed FBI director in 2001 by President George W. Bush and stayed on beyond his 10-year term at the request of President Barack Obama, ultimately retiring in 2013. The Justice Department said Mueller has resigned from his job at a private law firm to take the job of special counsel. As special prosecutor, Mueller will have all the same powers as a U.S. attorney, though he will still ultimately report to Rosenstein. Still, he is not subject to the day-to-day supervision of the Justice Department. He can keep the same investigators in place, or request new or additional staff including from outside the department. He will request a budget that includes personnel. Rosenstein appointed Mueller under a statute that has been used only once, in 1999, when John C. Danforth was appointed to investigate allegations of government wrongdoing in the siege at the Branch Davidian compound in Waco, Texas. Danforth's investigation cost millions of dollars and included hundreds of interviews and a restaging of the final hours of the 51-day standoff with federal agents. He ultimately produced a 150-page report clearing then-Attorney General Janet Reno and other top government officials of any responsibility. Lawmakers of both parties praised the announcement, with Sen. Dianne Feinstein, the top Judiciary Committee Democrat, saying there was "no better person who could be asked to perform this function." "He is respected, he is talented and he has the knowledge and ability to do the right thing," she said in a statement.House Speaker Paul Ryan says he supports the appointment of a former FBI director as special counsel investigating allegations that Russia and Donald Trump's presidential campaign worked together to affect last year's election. The Wisconsin Republican says in a written statement that he has wanted investigations that "follow the facts wherever they lead." He says the Justice Department's naming of Robert Mueller late Wednesday as special counsel is consistent with that goal. Ryan declined to call for a special prosecutor in remarks to reporters earlier in the day and warned against "rushing to judgment." He also said "it is obvious" that some people want to harm Trump. In his written statement, Ryan says the House investigation will continue. Sen. Richard Burr, a North Carolina Republican and chairman of the Senate intelligence committee, called the appointment a "good decision." "By having somebody like Bob Mueller head whatever investigation assures the American people that there's no undue influence, be it here, be it at the other end of Independence Avenue or within the Justice Department or FBI," said Burr, whose committee has been conducting its own investigation into Russia's election interference and possible ties with the Trump campaign. Minority Leader Nancy Pelosi said in a statement Wednesday that Mueller is "a respected public servant of the highest integrity." She adds that "a special prosecutor is the first step, but it cannot be the last. Director Mueller will still be in the chain of command under the Trump-appointed leadership of the Justice Department." Rep. Elijah Cummings of Maryland, the top Democrat on the Oversight Committee, calls Mueller a "solid choice," and commends Deputy Attorney General Ron Rosenstein for putting "our country and justice system first." GOP House Oversight Chairman Jason Chaffetz said Mueller "is a great selection. Impeccable credentials. Should be widely accepted." U.S. Senator of New York Kirsten Gillibrand tweeted, "Important step in the right direction. We need to get to the bottom of this mess." Congressman Erik Paulson of Minnesota tweeted "This is a step forward in restoring public confidence to look in to this matter. He is a well-equipped and highly respected on both sides." U.S. Senator Bob Casey of Pennsylvania tweeted, "I commend @TheJusticeDept for taking the appropriate step of appointing a special counsel." U.S. Senator Chuck Schumer tweeted, "A special counsel is very much needed in this situation and Deputy Attorney General Rosenstein has done the right thing." U.S. Senator Bob Corker of Tennessee tweeted, "I look forward to hearing from Deputy AG Rosenstein about his decision to appoint a special counsel when he briefs the Senate tomorrow." U.S. Senator Susan Collins of Maine tweeted, "Excellent choice for special counsel by Deputy AG. Fmr FBI Director Bob Mueller has sterling credentials & is above reproach #mepolitics." U.S. Senator Jeff Merkley of Oregon tweeted, "This is a victory for all Americans who believe in the integrity of the rule of law."