Venezuela's armed forces have barricaded a bridge on the country's western border with Colombia, in a dramatic attempt to prevent a delivery of humanitarian aid.
It comes at a time when tensions in Venezuela are reaching boiling point, with the South American country in the midst of the Western Hemisphere's worst humanitarian crisis in recent memory.
The opposition government, led by Juan Guaido, has said it is preparing to deliver tens of millions of dollars in food and medicine over the coming days, with supplies donated by the U.S. and others being stocked in warehouses near the border.
In a tweet on Wednesday, U.S. Secretary of State Mike Pompeo said: "The Maduro regime must let the aid reach the starving people."
In addition to easing a devastating shortage of basic products in the crisis-stricken country, the opposition's proposed move to deliver aid is widely seen as an attempt to undermine Maduro's authority.
The socialist leader has long used subsidized food handouts as a tool to maintain the backing of his supporters.
"A delivery of humanitarian aid will test the loyalty of Venezuela's armed forces — this moment represents a tipping point," Diego Moya-Ocampos, principal political analyst for Latin America at IHS Markit, told CNBC via telephone.
"Food has been used as a political weapon to control the population and one of the many reasons Maduro has not allowed humanitarian aid into the country," he added.
Given the heightened political situation in Venezuela, major international relief organizations are reluctant to assist with humanitarian aid.
The International Committee of the Red Cross and Red Crescent Movement said in a joint statement over the weekend that it could not take part in a delivery effort, citing its shared "fundamental principles of impartiality, neutrality and independence."
It makes getting basic products into Venezuela, past Maduro's allied security forces and to those that need the aid most, extremely challenging.
"Guaido will have plenty of logistical support getting the aid to the Venezuelan border (but) it is still not exactly clear how the distribution within the country will be carried out," Tom Long, assistant professor in the department of politics and international studies at the University of Warwick, told CNBC via email.
"If the aid is seen as squandered or captured by particular interests, it could dampen the opposition's momentum," Long added.
Pressure is building on Maduro to step down. The socialist leader has overseen a long economic meltdown, marked by hyperinflation, mounting U.S. sanctions and collapsing oil production.
As a result, some 3 million Venezuelans have fled abroad over the past five years to escape worsening living conditions.
When asked whether Maduro's days as Venezuela's president are numbered, IHS' Moya-Ocampos replied: "It is as simple as this: With the support of the military, Maduro will stay in power."
More than 40 countries, including the U.S. and most Latin American and European countries, have now recognized Guaido as Venezuela's rightful interim president.
It has thrust the oil-rich, but cash-poor, country into uncharted territory — whereby it now has an internationally-recognized government, with no control over state functions, running parallel to Maduro's regime.
The untenable situation has even prompted Pope Francis to offer his services as a potential mediator, if Guaido and Maduro both asked for his assistance.
Francis told reporters on the papal plane on Tuesday: "We are always willing."