Juan Guaido, head of the Opposition-run Congress, took an oath swearing himself in as Venezuela's interim president on Wednesday, as hundreds of thousands marched to demand the end of socialist leader Nicolas Maduro's government.
Guaido had said he would be willing to assume the presidency on an interim basis with the support of the armed forces to call elections.
U.S. President Donald Trump also issued a statement supporting Guaido, and encouraged other Western governments to recognize Guaido as interim president.
Within minutes, Canada recognized Guaido in the role. Foreign Affairs Minister Chrystia Freeland later issued a statement saying Canada supports Guaido's "commitment to lead Venezuela to free and fair presidential elections" and called on Maduro to cede power.
Argentina, Brazil, Chile, Colombia, Costa Rica, Guatemala, Honduras, Panama, Paraguay and Peru indicated they too will recognize Guaido. Ecuador joined that list a few hours later.
A spokesman for Mexico's foreign ministry said Mexico does not plan to change its policy on Venezuela "for the time being."
Bolivia's president also affirmed his solidarity with Maduro in a tweet. Cuba, El Salvador and Nicaragua appeared to be standing with Maduro, at least for now.
Demonstrators clogged avenues in eastern Caracas, chanting "Get out, Maduro" and "Guaido, Presidente" while waving national flags. Police fired tear gas to disperse protesters in several areas.
An Opposition spokesman said seven people had been killed during the day of demonstrations, including four killed by gunfire in the southwestern city of Barinas.