Venezuela's National Assembly president Juan Guaido gestures before a crowd of opposition supporters during an open meeting in Caraballeda, Vargas State, Venezuela, on January 13, 2019.
Washington CNN  — 

President Donald Trump is considering recognizing Venezuela’s opposition leader as the legitimate president of the country, three sources familiar with the matter told CNN, a significant move that would increase pressure on Venezuela’s President Nicolas Maduro.

Trump is weighing recognizing the country’s National Assembly President Juan Guaido as the legitimate Venezuelan leader after Maduro, a socialist authoritarian who has presided over Venezuela’s political and economic crisis, was sworn in last week for a second term.

The Venezuelan opposition, the United States and dozens of other countries have decried Maduro’s presidency illegitimate and the country’s constitution says a presidential vacancy can be filled by the president of the National Assembly.

National Security Council spokesman Garrett Marquis declined to confirm that Trump is weighing this step, but said the US has “expressed its support for Juan Guaido, who as President of the democratically-elected National Assembly has courageously declared his constitutional authority to invoke Article 233 and call for free and fair elections.”

The Trump administration is also considering leveling its harshest set of sanctions yet against Venezuela’s oil industry, weighing actions as severe as a full-fledged embargo of Venezuelan oil, two sources briefed on the matter said.

The Trump administration has previously weighed imposing sanctions against Venezuelan oil, but Trump ultimately rejected taking that additional step after an internal analysis showed it would lead to an increase in US gas prices. A full oil embargo would cause gas prices to rise by 15 cents a gallon for about six months, a former senior administration official said of the analysis.

“The United States is currently considering all diplomatic, political, and economic tools in its arsenal in response to the usurpation of power by the illegitimate Maduro regime,” Marquis said when asked if the US was considering an oil embargo.

The regional Organization of American States has said it won’t recognize Maduro’s term. The May 2018 election that returned him to power was boycotted by opposition groups and largely discredited by opponents in Venezuela, with hundreds of complaints of election violations and a low turnout.

The Organization of American States said last week that its member nations voted 19-6, with eight abstentions, to not recognize the legitimacy of Maduro’s government. One of those nations, Paraguay, announced Thursday it was breaking diplomatic relations with Venezuela and closing its embassy there.

Maduro defended his legitimacy in a speech last week after his swearing-in in Caracas, decrying what he called a “permanent campaign of lies” about him and his late predecessor, Hugo Chavez.

“We’re a real democracy and I, Nicolas Maduro Moros, I am a truly democratic president,” he said in a televised address.

John Bolton, the US national security adviser, has been one of the top proponents of ratcheting up US actions against Venezuela to bring more pressure to bear on the Maduro regime, the sources said.

And Republican Sen. Marco Rubio on Tuesday said he asked Trump to recognize Guaido as “the legitimate transitional President of Venezuela if the National Assembly invokes Article 233 of the constitution.”

The Trump administration has been laying the groundwork to recognize Guaido as the legitimate Venezuelan leader over the past week, with Vice President Mike Pence, Secretary of State Mike Pompeo and Bolton issuing a series of statements.

In a statement on Friday, Bolton expressed US support for “the courageous decision of the National Assembly President, Juan Guaido, to invoke protections under Venezuela’s constitution and declare that Maduro does not legitimately hold the country’s presidency.”

And after Guaido was briefly detained Sunday by Venezuelan government operatives, Pence lambasted Maduro as a “dictator with no legitimate claim to power” and reiterated Bolton’s support for Guaido.

As the US weighs recognizing Guaido, it must also contend with whether the Venezuelan opposition – which has been divided on whether Guaido should be sworn in as president while Maduro remains in office – is ready to take the step.

CNN’s Claudia Dominguez contributed to this report.