Venezuelan opposition leader Juan Guaido is calling for nationwide demonstrations on Monday to coincide with his planned return to the country.

Guaido on Sunday tweeted that Venezuelans should monitor his official announcements and that he would provide details about meeting points for supporters. He said they should gather across the country at 11 a.m.

Guaido was in Ecuador on Saturday as part of a tour of Latin American countries designed to increase pressure on Venezuelan President Nicolas Maduro to resign.

Guaido is the leader of the National Assembly who has declared himself president. He says Maduro must quit so that Venezuela can recover from its political and humanitarian crisis. Maduro says Guaido is part of a U.S.-backed plot to overthrow his government.