Guaido, the leader of Venezuela’s opposition-controlled National Assembly, invoked the constitution to assume an interim presidency in January, triggering a power struggle with Maduro. He has the support from about 50 countries, including the United States and several European nations, who have disavowed Maduro’s presidency.

Meanwhile, Maduro, who is backed by Russia and China, calls Guaido a U.S.-backed puppet who seeks to oust him in a coup. He has appeared to retain control of state institutions and the loyalty of senior military officers.

The Venezuelan government has arrested Guaido’s top aide, stripped the opposition leader of his parliamentary immunity and opened multiple probes against him. He has also barred him from leaving the country – a ban that Guaido openly violated earlier this year when he traveled to several Latin American countries seeking foreign support.

Home to the world’s largest oil reserves, Venezuela was for decades an economic leader in the western hemisphere and, despite a massive gap between rich and poor, was a major destination for neighboring Colombians and other Latin Americans fleeing their less prosperous and more troubled homelands.

But in 1999 with the rise to power of late leader Hugo Chávez – whose social and economic reforms initially endeared him to the poor but also set up an unsustainable system of state spending – Venezuela’s economy began to creep toward a crisis.

Fox News’ John Roberts, Kevin Corke, Andrew O’Reilly and the Associated Press contributed to this report.