Mass protests against the Venezuelan government erupted Tuesday after U.S.-backed opposition leader Juan Guaido called on the population to take to the streets against President Nicolas Maduro. "The United States stands with the People of Venezuela and their Freedom!" President Donald Trump tweeted. Guaido's call sparked clashes between thousands of protesters and forces supporting Maduro. By Tuesday evening, Guaido claimed that Maduro had lost the support of the country's armed forces, and he called on the military to "keep advancing" in "operation freedom." There was, however, no immediate indication that Guaido's side had widespread military support, nor that it intended to take power through force. The opposition leader called on supporters to take to the streets again on Wednesday.

Venezuelan opposition leader and self-proclaimed acting president Juan Guaido (C) speaks to supporters next to high-profile opposition politician Leopoldo Lopez, who had been put under home arrest by Venezuelan President Nicolas Maduro's regime, and members of the Bolivarian National Guard who joined his campaign to oust Maduro, in Caracas on April 30, 2019. Cristian Hernandez | AFP | Getty Images

There is "overwhelming support for Guaido," said national security advisor John Bolton, who added that it "needs to be translated into a peaceful transition of power" away from Maduro, who has refused to yield the presidency. Bolton also denied that the protests constitute a coup, as Maduro claims, and warned that it "would be a big mistake" for Maduro to order his troops "to use force against innocent civilians." "All options remain on the table" for America, Bolton added without providing detail.

Supporter of Venezuelan opposition leader and self-proclaimed acting president Juan Guaido clash with forces loyal to President Nicolas Maduro after members of the Bolivarian National Guard joined Guaido's campaign to oust him, in front of La Carlota military base in Caracas on April 30, 2019. on April 30, 2019. FEDERICO PARRAFederico Parraf | AFP | Getty Images

In a Twitter post following his remarks outside the White House, Bolton threatened officials in the Maduro regime: "Your time is up. This is your last chance. Accept Interim President Guaido's amnesty, protect the Constitution, and remove Maduro, and we will take you off our sanctions list. Stay with Maduro, and go down with the ship." Bolton TWEET The Washington Post, citing a Caracas Metropolitan Clinic official, reported that six people were being treated for injuries sustained by tear gas and rubber bullets. News outlets showed video of an armored vehicle ramming a crowd of pro-Guaido demonstrators in the capital city of Caracas. NBC News TWEET armored car In an early-morning video, Guaido, standing at an air base in Caracas in front of armed men in military garb, called on soldiers and civilians to oust Maduro, "based on the nonviolent struggle that we have done at all times." In January, Trump officially recognized Guaido as the legitimate interim president of oil-rich Venezuela, and vowed to "hold the illegitimate Maduro regime directly responsible for any threats it may pose to the safety of the Venezuelan people." Trump TWEET I am monitoring the situation in Venezuela very closely. The United States stands with the People of Venezuela and their Freedom! Trump followed up with a threat against Cuba on Tuesday afternoon, tweeting that the U.S. will place "a full and complete embargo, together with highest-level sanctions" on the island nation unless Cuban troops cease their conduct in Venezuela. Trump TWEET Cuba Senior Trump administration officials voiced support for Guaido's "Operation Liberty" on Tuesday. "We are with you!" Vice President Mike Pence tweeted.

Members of the Bolivarian National Guard who joined Venezuelan opposition leader and self-proclaimed acting president Juan Guaido in his campaign to oust President Nicolas Maduro, are greeted by opposition supporters, in Caracas on April 30, 2019. Christian Hernandez | AFP | Getty Images

Secretary of State Mike Pompeo endorsed Guaido's call to move ahead with the plan to oust Maduro, saying in a tweet that the U.S. "fully supports the Venezuelan people in their quest for freedom and democracy." Bolton shared Guaido's video on his Twitter account, adding: "Venezuela's armed forces should stand loyal to their people and the constitution. Democracy will be restored in Venezuela." Bolton TWEET Maduro, a leftist, has refused to give up his hold on power. In a tweet Tuesday morning, he vowed to "overcome" the attempted uprising and claimed he had the support of military commanders who "have shown me their total loyalty to the People, to the Constitution and to the Homeland." Maduro TWEET ¡Nervios de Acero! He conversado con los Comandantes de todas las REDI y ZODI del País, quienes me han manifestado su total lealtad al Pueblo, a la Constitución y a la Patria. Llamo a la máxima movilización popular para asegurar la victoria de la Paz. ¡Venceremos!