The United States on Wednesday imposed sanctions on five Iranian ship captains who delivered oil to Venezuela, and Secretary of State Mike Pompeo reaffirmed Washington's backing for Venezuelan opposition leader Juan Guaido.Speaking at a news conference, Pompeo said the ships delivered about 1.5 million barrels of Iranian gasoline and related components, and warned mariners against doing business with the government of Venezuelan President Nicolas Maduro, whose ouster Washington seeks."As a result of today’s sanctions, these captains’ assets will be blocked. Their careers and prospects will suffer from this designation," Pompeo said in a statement later."We will continue to support the National Assembly…