Venezuelan opposition deputies wave while traveling in a caravan of buses heading to the border with Colombia to bring in US-supplied humanitarian aid, in Caracas on February 21, 2019. - On Maduro's orders, the military has beefed up border security and barricaded a major border bridge to prevent the supplies from entering the country from Cucuta, Colombia, where tons of supplies are stockpiled. Although it was unclear exactly what opposition leader and self-declared acting president Juan Guaido intends to do, he says he has enlisted hundreds of thousands of volunteers in recent days to help bring in and distribute the aid. (Photo by YURI CORTEZ / AFP)