By Simon Lewis and Humeyra Pamuk WASHINGTON (Reuters) -The United States distanced itself on Wednesday from a visit by former U.S. ambassador to the United Nations Bill Richardson to Russia where WNBA star Brittney Griner and former U.S. Marine Paul Whelan remain jailed. Richardson, who has privately worked to secure the release of American detainees abroad, held meetings there this week, according to a source familiar with the matter. The U.S. State Department indicated that any outside effort to help secure the release of detained Americans abroad should be fully coordinated with it and that…