Russia ambassador to State : Russian official said Russian president must go . Georgian foreign minister made comment to Joe Vaccarello , ambassador says . Russian ambassador objects to disclosure of conversation . Russia said at least 2,000 people have been killed in South Ossetia 's capital , Tskhinvali . U.S. ambassador asks if Russia seeking `` regime change ; '' drawing Russian retort .
Russia ambassador to State : Russian official said Russian president must go . Georgian foreign minister made comment to Joe Vaccarello , ambassador says . Russian ambassador objects to disclosure of conversation . U.S. ambassador asks if Russia seeking `` regime change ; '' drawing Russian retort .