CARACAS -- Stymied in trying to advance his anti-U.S. agenda in Latin America, Venezuelan President Hugo Chávez is tightening the screws at home -- and touring friendly autocratic regimes abroad.

Opponents are organizing a massive march for Saturday in Caracas, disregarding warnings by Venezuela's top federal prosecutor that protesters could face prison sentences of up to 24 years for disturbing the peace.

``We dare the government to put into prison not only the leaders of the 25 groups heading up the march but the hundreds and hundreds of people who will call for a democratic end to this government,'' Henry Ramos, head of the Acción Democrática political party told a crowd of supporters on Wednesday.

Chávez won't be in Venezuela to hear these calls, however. He is in the midst of visiting friendly autocracies in Africa, the Middle East and Europe.

Chávez began this trip after failing to convince other South American presidents at a regional summit last week to condemn the expanded U.S. military presence planned for neighboring Colombia.

Not winning their backing marked the latest in a string of defeats for Chávez in Latin America, including the ouster of Honduran President Manuel Zelaya, a key ally in Central America.

Analysts don't expect Chávez to retreat despite the setbacks.

``Chávez is most dangerous not when he's strong but when he's weak,'' said Matias Spektor, a foreign policy specialist at the Getulio Vargas Foundation in Rio de Janeiro. ``He needs to show the grand gesture and crack down at home.''

Chávez thought he could capitalize on the leaked word that Colombia was planning to allow U.S. troops to have access to seven of its military bases throughout the country. U.S. allies such as Brazil and Chile, reflecting age-old regional resentments against Uncle Sam, voiced concern about the agreement.

The summit's final declaration didn't condemn the U.S.-Colombian deal, as Chávez sought. Instead, it called for strengthening the fight against terrorism and drug trafficking -- Uribe's main goals -- while saying that foreign powers couldn't threaten other nations.

``Bariloche was a defeat for Chávez,'' said Maria Teresa Romero, a foreign policy specialist at Venezuela's Central University in Caracas. ``Uribe emerged in a more advantageous position.''

Rafael Nieto, a political columnist for Colombia's main newspaper, El Tiempo, said Chávez had already lost ground in Latin America when Honduras' military forced Zelaya into exile at gunpoint on June 28, the same day that Argentine voters handed a stinging election defeat to Argentine President Cristina Fernández de Kirchner, another of his allies.

On top of that, Nieto added, Paraguay's Senate recently blocked Chávez's move to join the Mercosur trade bloc, and El Salvador's new leftist president, Mauricio Funes, declared Brazilian President Luiz Inácio Lula da Silva to be his model, not Chávez.

``Chávez's authoritarian measures in Venezuela scare people in other countries,'' Nieto said.

That doesn't seem to be the case in the countries he's visiting during his 11-day trip. Libyan President Moammar Gadhafi awarded him a medal, and Algeria's president discussed strengthening oil ties.

Still to come: Iran, Belarus and Russia.