Robert O'Brien disputes account of briefing in which lawmakers were reportedly told that Moscow is trying to get president re-elected

Richard Grenell will temporarily head US intelligence apparatus, despite no experience in the field; White House defends decision as Democrats accuse him of endangering country

New York Times says president berated outgoing intelligence chief for briefing lawmakers, including Democrats, on concerns regarding repeat meddling operation

White House allegedly tried to cover up details of president's phone call; intelligence chief Joseph Maguire calls whistleblower complaint 'unprecedented' amid impeachment calls