title: Venezuela's former ambassador to U.N. leaves the United States: source
text: HOUSTON (Reuters) - Venezuela s former ambassador to the United Nations, Rafael Ramirez, has left the United States after being forced to resign by President Nicolas Maduro s government, according to a source with knowledge of his travel plan. Ramirez, who for more than a decade ran OPEC member Venezuela s massive oil industry, said earlier on Tuesday he was removed because of his opinions. 