US Special Counsel Robert Mueller said on Wednesday his investigation into Russia's interference in the 2016 election was never going to end with criminal charges against President Donald Trump and that he would give no more information than was already published in his report. In his first public comments since starting the investigation in May 2017, Mueller said Justice Department policy explicitly prevented him from bringing charges against a sitting president. "Charging the president with a crime was therefore not an option we could consider," Mueller told reporters as he announced his resignation from the Justice Department. 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 engage in 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. "If we had confidence that the president clearly did not commit a crime we would have said so. We did not, however, make a determination as to whether the president did commit a crime," Mueller said. He said the 448-page report spoke for itself. "Beyond what I've said here today and what is contained in our written work, I do not believe it is appropriate for me to speak further," Mueller said in a brief press appearance at the Justice Department's headquarters. He did not take questions. Trump, who has repeatedly denounced Mueller's probe as a witch hunt, said the matter was settled. "Nothing changes from the Mueller Report," he said on Twitter. "There was insufficient evidence and therefore, in our Country, a person is innocent. The case is closed! Thank you." Since the report's release, Democrats have debated whether to bring impeachment charges against Trump or simply continue their multiple investigations into his administration and his private business. "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 House Judiciary Committee Chairman Jerrold Nadler. Representative Justin Amash, the only Republican to have said publicly that Trump has committed impeachable offenses, tweeted: "The ball is in our court, Congress." The investigation ensnared dozens of people, including several top Trump advisers and a series of Russian nationals and companies. Among them are his former campaign chairman, Paul Manafort, who is serving 7 1/2 years in prison for financial crimes and lobbying violations, and his former personal lawyer, Michael Cohen, who recently began a three-year sentence for campaign-finance violations and lying to Congress. Since the report's release, Democratic lawmakers have tried without success to get the full report and underlying evidence. The House Judiciary Committee also is negotiating for Mueller to testify at a hearing. Trump has said Mueller should not testify before Congress but that the final decision was up to Attorney General William Barr. Democrats have denounced Barr, saying he misrepresented the special counsel's findings. Mueller appeared to have misgivings at one point as well, complaining to Barr in March that he had initially disclosed his main findings in an incomplete way that caused public confusion. In congressional testimony in April, Barr dismissed Mueller's concerns as "a bit snitty." Barr now is leading a review of the origins of the Russia investigation in what is the third known inquiry into the FBI's handling of the matter. Trump harbors suspicions that the Democratic administration of President Barack Obama started the investigation in 2016 to undermine his presidency. — Reuters