A Venezuelan official said on Monday that the country is banning sea trips to and from three Dutch Caribbean islands — a region that has been linked to efforts to undermine President Nicolás Maduro by sending emergency aid to the South American nation.

USAID humanitarian aid is stored at a warehouse next to the Tienditas International Bridge on the outskirts of Cucuta, Colombia, on the border with Venezuela, Monday. The US military airlifted tons of humanitarian aid as part of an effort meant to undermine socialist President Nicolás Maduro and back his rival for the leadership of Venezuela. (Photo: AP)

The indefinite shutdown of the “maritime border” applies to commercial and fishing boats between Venezuela and the islands of Curacao, Aruba and Bonaire, said Falcon state Civil Protection Director Gregorio Jose Montano.

It comes as opposition leader and self-proclaimed president of Venezuela, Juan Guaidó, has been rallying international support for his challenge to Maduro. Guaido has called for international emergency aid for Venezuela, including from Curacao, about 40 miles (65 kilometres) from Venezuela.

Maduro vows to block the aid, saying it’s part of a US-led coup. Dutch officials have said they’re opening Curacao as a hub for emergency shipments.

Guaidó also says that he’s organising caravans to try to bring in the emergency food and medicine from the United States and other countries, starting on Saturday. It’s expected also to come into Venezuela through Brazil and the Colombian border town of Cucuta, where supplies are being warehoused.

Maduro has said the aid is unnecessary, denying a humanitarian crisis in Venezuela.

The Maduro Government last year temporarily closed air and maritime ties with the three islands, saying it was trying to stamp out smuggling of Venezuelan products to the islands.