BLOOMBERG ‐ Venezuelan President Nicolas Maduro started closing the nation’s entry points on Thursday and soldiers blocked the movements of National Assembly leader Juan Guaido as opposition supporters prepared to bring humanitarian aid across the borders.

Three buses carrying lawmakers sympathetic to Guaido left Caracas heading for the town on the Colombian border that’s the focus of the aid effort, but were stopped in Carabobo state. Guaido, traveling separately for security reasons, was held up by army trucks blocking a tunnel east of the capital, said Edward Rodriguez, a spokesman.

Maduro, who has said the aid effort is a pretext for a U.S. intervention, also announced that Venezuela’s land crossings with Brazil would shut at 8 p.m., and said he was also weighing "a total closure of the border with Colombia." He already had sealed off access from Curacao, Aruba and Bonaire.

Maduro’s government and the resurgent opposition are readying for a showdown this weekend over donated food and medicine stockpiled in neighboring Colombia, Brazil and Curacao. Maduro’s government says that the ravaged country has no need of help, despite widespread shortages, while U.S. President Donald Trump has demanded that the Venezuelan military allow the aid in, warning that "all options are open" in the event they refuse.