CUCUTA, Venezuela — Venezuela’s opposition and activists prepared on Saturday to confront troops stationed along the country’s borders to block their plan to bring in food and medicine that authorities are calling a veiled US-backed invasion.

Opposition volunteers in neighboring Brazil and Colombia plan to arrive at the border to help carry humanitarian aid to a sick and hungry population suffering from an economic meltdown under President Nicolas Maduro. While the need for basic food and medicines is real, the effort is also meant to embarrass military officers who continue to support Maduro’s increasingly isolated government.

Juan Guaido, recognized by most Western nations as the country’s legitimate head of state, defied court orders not to leave Venezuela by arriving on Friday in the Colombian border city of Cucuta, where aid from the US and Colombian governments is stockpiled in warehouses.

Guaido, 35, head of the opposition-run Congress, has provided few details on the transport plan. Trucks are expected to be driven by Venezuelan volunteers and some opposition figures have suggested forming human chains.

“Today the obstacles that the dictatorship created will tomorrow be rivers of unity, of peace,” Guaido said in a news conference on Friday in Cucuta, where he was received by Colombian President Ivan Duque.

Venezuelan soldiers may bar the way.

Vice President Delcy Rodriguez said in a tweet late on Friday that Venezuela’s government shut the Tachira border that connects it with Cucuta temporarily “due to a series of illegal threats” by Colombia.

A group of frustrated Venezuelans who were seeking to cross into Colombia on Saturday to work morning threw rocks and bottles at National Guard troops, who responded with tear gas.

“We were all going to work, we want to work, the people attempted to force through,” said Viviana Meza, 29, who works in a Cucuta restaurant.

At least four National Guard officers on Saturday at the border disavowed Maduro’s government and requested assistance from the Colombian government, Colombia’s migration agency said on Saturday. Videos on social media showed crowds first jeering and then cheering the men as they were escorted away by Colombian police. — Reuters