U.S. Secretary of State John Kerry visits with students at the U.S. booth set up as part of the U.S. embassy's education and cultural programme, during Feria de las Culturas Amigas at Zocalo plaza in Mexico City May 21, 2014. Impatience with the Venezuelan government is growing over its "total failure" to show good faith in talks to resolve the country's political crisis, Kerry said on Wednesday. REUTERS/Carolyn Kaster/Pool (MEXICO - Tags: POLITICS EDUCATION)