Kerry meets Venezuela's Maduro amid vote tensions

By Patricia Zengerle CARTAGENA, Colombia (Reuters) - U.S. Secretary of State John Kerry met Venezuelan President Nicolas Maduro on Monday, the first formal encounter between the two since Kerry became the top U.S. diplomat. "(Kerry) spoke of our concern about the economic and political challenges that have affected millions of Venezuelans, and he urged President Maduro to work constructively with opposition leaders to address these challenges," said State Department Spokesman John Kirby. Kerry a