In a televised speech Thursday, Maduro announced the Brazil border closure and warned against trying to bring humanitarian supplies into Venezuela by force. “I don’t want to make such a decision, but I am considering it — an absolute closure of the border with Colombia,” he said. “We have taken all the measures so that everything can be peaceful,” he added.Foreign aid is currently being assembled in both Brazil and Colombia for hungry Venezuelans, at the call of opposition leader and self-declared president Juan Guaido. Despite accepting aid from the United Nations last year, Maduro opposes the new aid shipments and has described the opposition’s aid campaign as “a provocation.” Guaido has named Saturday as the deadline for the aid to cross the border.Venezuela has already closed its air and maritime borders with Curacao, Guaido’s third declared collection point for humanitarian aid, as well as the islands of Aruba and Bonaire. Blocking the road toward ColombiaAs the aid delivery deadline approaches, the spotlight is on the Colombian border town of Cucuta, where several shipments of US aid are waiting to be delivered and Virgin CEO Richard Branson is expected to host a solidarity concert for Venezuela.Guaido is already en route to Cucuta, with plans to “welcome the humanitarian aid,” his spokesman Edward Rodriguez told CNN. But for many of his supporters, even approaching the border may be a struggle; on Thursday, Venezuela’s National Guard also blocked access to the La Cabrera tunnel, after a convoy of buses transporting members of the opposition-led National Assembly tried to pass through, according to video footage obtained by CNN from VPI TV.The buses were blocked for more than 30 minutes before the caravan was permitted to continue, the footage shows.CNN has reached out to Venezuela’s Ministry of Communications for comment about the incident.The Venezuelan military remains loyalThe question hanging over Guaido’s aid plan remains: How to move anything across the Venezuelan border ? Several protests have broken out in the streets of the country since the crisis, calling on Maduro to let the humanitarian aid shipments into the economically crippled country.But the United Nations and Red Cross have so far refused to get involved, insisting that humanitarian aid should be free from political maneuvering. “We follow humanitarian principles of where aid should be distributed independent of political, military, or any other objectives,” UN spokesman Stephane Dujarric told reporters in New York this week.And Venezuela’s military remains loyal to Maduro, despite calls to defect by the opposition and the Trump administration.”Is Trump the commander in chief of the Venezuelan armed forces?” Maduro asked in his speech Thursday. “The answer is obvious. And the answer to imperialism is also obvious.” “We just want peace and tranquility,” he added.CNN’s Richard Roth and Stefano Pozzebon contributed to this report.