(CNN) Attorney General Jeff Sessions met twice last year with the top Russian diplomat in Washington whose interactions with President Donald Trump's former national security adviser Michael Flynn led to Flynn's firing, according to the Justice Department. Sessions did not mention either meeting during his confirmation hearings when he said he knew of no contacts between Trump surrogates and Russians. A Justice official said Sessions didn't mislead senators during his confirmation. The revelation prompted key Democrats to call for Sessions' resignation, including Senate Minority Leader Chuck Schumer and House Minority Leader Nancy Pelosi. "Last night when I read the revelations ... and his decision to mislead Congress without those contacts, I felt a knot in the pit of my stomach," Schumer told reporters Thursday. "The information reported last night makes it clear, beyond the shadow of a doubt, that Attorney General Sessions cannot possibly lead an investigation ... with these revelations, he may very well become the subject of it."The diplomat's interactions with former Trump national security adviser Mike Flynn led to Flynn's firingThe Justice Department disclosed the meetings
_ was an early Trump backer and regular surrogate for him as a candidate.