WASHINGTON (Reuters) - Jason Chaffetz, chairman of the House of Representatives Oversight and Government Reform Committee, said on Thursday that U.S. Attorney General Jeff Sessions should “clarify his testimony” about his contacts with Russian officials during the Trump presidential campaign. Chaffetz, a Utah Republican, said in a Twitter post, “AG Sessions should clarify his testimony and recuse himself.” Democrats have called for an independent investigation into possible ties between Russia and the Trump campaign.  U.S. House Democratic leader Nancy Pelosi called on Sessions to resign on Wednesday after the Washington Post reported he failed to disclose two meetings he had with Russia’s ambassador before Donald Trump was inaugurated as president. 