Venezuela's military said Tuesday it was on alert at its frontiers following threats by US President Donald Trump and suspended air and sea links with the island of Curacao ahead of a planned aid shipment.
Opposition leader and self-declared interim president Juan Guaido has vowed to bring aid in from various points Saturday "one way or another" despite military efforts to block it.
But commanders doubled down on their allegiance to President Nicolas Maduro after Trump urged them to abandon him.
"The armed forces will remain deployed and on alert along the borders... to avoid any violations of territorial integrity," said Defense Minister Vladimir Padrino.
Regional commander Vladimir Quintero later confirmed media reports that Venezuela had ordered the suspension of air and sea links with Curacao and the nearby Netherlands Antilles islands of Aruba and Bonaire.
Shipments of food and medicine for Venezuelans suffering in the country's economic crisis have become a focus of the power struggle between Maduro and Guaido.
Aid is being stored in Colombia near the Venezuelan border and Guaido aims also to bring in consignments via Brazil and Curacao, wh9ich is off the coast of Venezuela.
A Brazilian presidential spokesman said the country was cooperating with the United States to supply aid to Venezuela but would leave it to Venezuelans to take the goods over the border.
Maduro says the aid plan is a smokescreen for a US invasion. He blames US sanctions and "economic war" for Venezuela's crisis.
Guaido, the 35-year-old leader of the Venezuelan legislature, has appealed to military leaders to switch allegiance to him and let the aid through.