Venezuela’s opposition is calling on the United States and allied nations to consider using military force to topple the government of Venezuelan President Nicolás Maduro. This comes as U.S. Vice President Mike Pence heads to Bogotá, Colombia, today to discuss next steps with regional leaders and Venezuelan self-proclaimed president, opposition leader Juan Guaidó.

The meeting comes after a dramatic weekend which saw the Venezuelan military blocking the delivery of so-called humanitarian aid from entering the country at the Colombian and Brazilian borders. At least four people died after clashes broke out between forces loyal to Maduro and supporters of the opposition. The United Nations, the Red Cross and other relief organizations have refused to work with the U.S. on delivering aid to Venezuela, which they say is politically motivated. Over the weekend, U.S. officials ramped up pressure on the Maduro government.