Burr says Flynn lawyers told committee he wont honor subpoena for documents

Trump calls probe a "witch hunt"

U.S. Senate Select Intelligence Committee chairman Sen. Richard Burr (R-N.C.)

WASHINGTON, D.C. — The Senate Intelligence Committee is still negotiating with former national security adviser Michael Flynn to obtain documents for its counterterrorism investigation into Russia and the U.S. presidential election, congressional aides said on Thursday.Earlier on Thursday, the committee’s Republican chairman, Sen. Richard Burr (R-N.C.), told reporters that Flynn’s lawyers said he would not honor a subpoena for the documents. A lawyer for Flynn did not immediately respond to Reuters’ request for comment.The Senate Intelligence Committee’s counterterrorism probe took on added significance after President Donald Trump dismissed FBI Director James Comey last week amid allegations of Russian meddling in the 2016 U.S. presidential election. Former Director of National Intelligence James Clapper and Sen. Diane Feinstein (D-Calif.) of the Senate Intelligence Committee have publicly said that so far they have seen no evidence of collusion between the Trump campaign and Russian officials. The House of Representatives intelligence panel is conducting a similar probe.On Tuesday, Deputy Attorney General Rod Rosenstein, the No. 2 Justice Department official, named former FBI Director Robert Mueller to also investigate allegations of ties between Trump’s 2016 presidential campaign and Russia. The appointment comes amid mounting pressure from Democrats in Congress for a third, independent investigation beyond the existing FBI and congressional probes into the Russia issue.Mueller’s appointment was not expected to affect the FBI or congressional investigations, and his character was praised by lawmakers on both sides of the aisle.”The appointment of former FBI director and respected lawyer Robert Mueller … is a positive development and will provide some certainty for the American people that the investigation will proceed fairly and free of political influence,” said Burr and co-chair Sen. Mark Warner (D-Va.), leading members of the Senate committee investigating Russian influence, in a statement.Trump”s Twitter comments Wednesday night after the announcement of Mueller’s appointment said “a thorough investigation will confirm what we already know — there was no collusion between my campaign and any foreign entity.”On Thursday he called it “the single greatest witch hunt” in U.S. history.In two Twitter postings, the president assailed the latest development to roil his four-month-old administration.”With all of the illegal acts that took place in the Clinton campaign & Obama Administration, there was never a special councel [sic] appointed!” Trump wrote.”This is the single greatest witch hunt of a politician in American history!” added Trump, who said in a speech on Wednesday that “no politician in history” had been treated worse or more unfairly than he has.U.S. stocks rose as upbeat economic data emboldened investors to return to the market on Thursday, a day after Wall Street saw its worst selloff in eight months on worries that the political turmoil could sideline Trump initiatives such as tax cuts that investors see as favoring economic growth.Rosenstein was due to brief U.S. senators later on Thursday. Reuters News Service contributed to this report.