The United States has officially recognized Juan Guaido as Venezuela's interim leader after the opposition politician declared himself president during a day of mass demonstrations in the South American country."Today, I am officially recognizing the President of the Venezuelan National Assembly, Juan Guaido, as the Interim President of Venezuela," President Donald Trump said in a statement."We encourage other Western Hemisphere governments to recognize ... Guaido as the Interim President of Venezuela, and we will work constructively with them in support of his efforts to restore constitutional legitimacy," Trump added.The developments occurred as thousands of Venezuelans demonstrated in the streets of Caracas as part of a nationwide protest calling for the ouster of President Nicolas Maduro.Police lined streets and bridges in Caracas as opposition protesters threw objects at them and chanted "Get out Maduro" and other slogans.In the middle-class neighborhood of El Paraiso, National Guard troops launched tear gas at protesters who say they are angry over rising inflation, a shortage of basic goods and a migration crisis that has divided families.Counterprotests have also been organized by the Venezuelan government, which has accused the opposition of provoking violence.Maduro is facing mounting global criticism following his reelection last year that was widely considered illegitimate. The opposition believes their chances of forcing Maduro out of office have improved because of the country's economic crisis and its increasingly isolated position on the world stage.Wednesday's protests were scheduled to coincide with the 61st anniversary of the 1958 coup that overthrew military dictator Marcos Perez Jimenez.The anti-government protests are a crucial test for Guaido, the newly installed leader of Congress. Guaido and his followers hope to get the poor and the military to shift loyalties to their opposition movement. Any government change, however, depends on the allegiance of the armed forces, which have supported Maduro through two waves of street protests and an ongoing deconstruction of democratic institutions.Guaido has called on the military to repudiate Maduro and promised amnesty to those who help work toward restoring democracy to the financially strapped and oil-rich country.