Opposition leader Juan Guaido will make a fresh bid on Saturday to rally Venezuela's armed forces behind him with protests at military bases in the crisis-hit country.
The protest call by Guaido -- the head of the National Assembly legislature, who is recognized as interim president by more than 50 countries -- comes just days after he urged the military to rise up against the socialist president, Nicolas Maduro.
"Peacefully, civically... we are going to deliver a simple document, a proclamation to the Armed Forces to listen to the Venezuelan call, that a rapid transition is possible to produce free elections," Guaido told a press conference in Caracas.
A small group of military personnel heeded Guaido's call to rise up on Tuesday, but the effort petered out, triggering two days of protests against the government in which four people were killed and several hundred injured.
Venezuela's military leadership has since reiterated its support for the government, and Maduro is standing his ground.
The country's attorney general Tarek William Saab said Friday that 18 arrest warrants had been issued for "civilian and military conspirators" following the failed uprising, with lieutenant colonels among the uniformed personnel being sought.
Tensions in Venezuela have soared since Guaido, the 35-year-old head of the National Assembly, invoked the constitution to declare himself acting president on January 23, claiming Maduro's re-election last year was illegitimate.
The standoff has drawn in major world powers, with the US throwing its support behind Guaido and Russia and China backing Maduro.
The United States has imposed tough sanctions and Trump has refused to take the threat of military action off the table, in an intensifying campaign to drive Maduro out.
But President Donald Trump adopted a strikingly conciliatory tone after a more than hour-long conversation with Vladimir Putin on the Venezuela crisis, describing the Friday talks with his Russian counterpart as "very positive."
- 'People are starving' -
"He is not looking at all to get involved in Venezuela other than he'd like to see something positive happen for Venezuela," Trump said of Putin.
"And I feel the same way. We want to get some humanitarian aid. Right now people are starving."
Venezuela has suffered five years of recession marked by shortages of basic necessities as well as failing public services, including water, electricity and transport.
Trump's tone came in stark contrast to that of his top advisors, in particular Secretary of State Mike Pompeo who charged this week that Maduro had been poised to flee to Cuba, but was talked out of it by the Russians.
US-Russian tensions have spiked over the months-long standoff in Venezuela, and the Kremlin's assessment of the Trump-Putin call differed substantially from that coming from the White House.
"Interference in internal affairs, attempts to change the leadership in Caracas through force, undermine the prospects for a peaceful settlement of the conflict," said a Russian statement.
"Vladimir Putin stated that only the Venezuelan people have the right to decide the future of their country," it added.
The United States is insisting Maduro's days are numbered, but experts say its options for breaking the stalemate are limited, and that Washington may have overestimated the opposition leader's strength.