MOSCOW - US Ambassador to Russia Jon Huntsman has been forced to cancel a planned trip to Russia's Far East next week because senior regional officials could not find time to meet him, the US Embassy to Russia said in a statement on Friday.The United States has a consulate in Vladivostok in the Russian Far East and the embassy said his planned visit was part of a series of trips to places where the US hoped to resume consular operations which were suspended earlier this year amid a diplomatic dispute.