WASHINGTON, DC - NOVEMBER 26: U.S. Attorney General William Barr as U.S. President Donald Trump holds a signing ceremony for an executive order establishing the Task Force on Missing and Murdered American Indians and Alaska Natives, in the Oval Office of the White House on November 26, 2019 in Washington, DC. Attorney General Barr recently announced the initiative on a trip to Montana where he met with Confederated Salish Kootenai Tribe leaders. (Photo by Drew Angerer/Getty Images)

Federal prosecutor Nora Dannehy, a top aide to U.S. Attorney John H. Durham in his Russia investigation, has quietly resigned – at least partly out of concern that the investigative team is being pressed for political reasons to produce a report before its work is done, colleagues said.