Russia does not have \"anything to add\" to the political debate on Syria in the United States, a White House official said on Friday. Ben Rhodes, Obama\'s deputy national security advisor for strategic communications, made the comments after senior Russian lawmakers expressed a desire to visit Washington and persuade Congress not to approve military action against Syria. Rhodes also criticised Russia for \"refusing to take action\" on Syria at the United Nations and said that Moscow was \"avoid(ing) the core issues\".