washington special counsel investigate whether russia interfere u.s. presidential election possible collusion moscow trump campaign want speak current former senior white house officials new york time report saturday robert mueller special counsel lead investigation talk white house potential interview include former white house chief staff reince priebus newspaper say cite three unnamed source brief discussions spokespeople mueller white house immediately respond request comment mr mueller ask white house specific meet attend whether note transcripts document newspaper report cite two people mueller former head federal bureau investigation want learn trump decide fire jam comey fbi chief dismiss may accord paper interview yet set paper say trump call mueller investigation witch hunt allegations collusion trump associate moscow hound republican president since take office january present major distraction policy agenda russia repeatedly deny meddle u.s. election trump say collusion last month fbi raid home paul manafort trump former campaign manager collect evidence washington post report early week russia probe counsel want interview senior white house officials nyt