Nicolas Maduro has denounced his opponents in a speech at a military ceremony as opposition leader Juan Guaido escalated his campaign to topple the Venezuelan president.
Mr Maduro’s appearance came a day after his rival returned home to a tumultuous welcome.
Mr Guaido left Venezuela last month despite a court order banning him from foreign travel and visited Colombia, Brazil, Paraguay, Argentina and Ecuador.
Upon his return to Venezuela, Mr Guaido, the man who says he is the rightful president, made an appeal for support from state unions, long reliant on government handouts.
The Maduro government’s decision not to move against Mr Guaido on Monday reflects the intense pressure Mr Maduro faces, yet he was defiant during a ceremony marking the sixth anniversary of the death of his predecessor and mentor, Hugo Chavez.
He said government supporters would hold a rally on Saturday, a “day of anti-imperialism” in his words, and a counter to US-backed Mr Guaido’s plans to hold nationwide protests the same day.
Mr Maduro also pinned medals on members of the security forces involved in a crackdown on Mr Guaido’s failed February 23 attempt to bring humanitarian aid into Venezuela from Brazil and Colombia.
Mr Maduro has described the attempt, backed by the US and its allies, as part of a plot to overthrow his government.
Hours earlier, Mr Guaido said police officials were among those at a meeting that he held with leaders of public employee unions, which rely heavily on subsidies from Mr Maduro’s government to get by in a country suffering from hyperinflation and shortages of food and other necessities.
“We’re not going to collaborate any longer with the dictatorship,” Mr Guaido said after a meeting at the offices of an engineers’ association in Caracas.
He urged state workers to prepare for a strike, though no date was given and he said an immediate priority will be to promote a law guaranteeing rights for public workers.
The 35-year-old leader of the opposition-controlled National Assembly said he would call a meeting of the legislature on Wednesday to craft the law.
Mr Guaido and his backers say Mr Maduro’s re-election last year was invalid, making the legislative leader interim president.
At least one pro-Maduro Supreme Court judge has accused Mr Guaido of illegally usurping power, putting him at risk of arrest.
Mr Guaido had shrouded the route and timing of his return on Monday in secrecy amid concerns he might be detained.
Yet he breezed through airport immigration checks after a commercial flight from Panama and brazenly called for Mr Maduro’s downfall at a rally where the presence of security forces was minimal.
The United States and other countries had warned Mr Maduro not to move against his adversary, and he possibly realised arresting his foe could generate more street protests.
US Senator Marco Rubio, an influential voice in advocating US measures against Mr Maduro, warned that the Venezuelan government could still act against Mr Guaido in ways that it has refined against other opposition voices.
“Issue a standing arrest warrant from a rubber stamp court. Then at a time of their choosing, arrest him late at night with no media, diplomats or supporters around,” Mr Rubio warned in a tweet.
While Mr Guaido’s presence is likely to add at least short-term momentum to his campaign for political change, Mr Maduro has proven resilient and still controls the organs of state, including the critical loyalty of top military officers.
Some analysts speculate the two sides might consider behind-the-scenes negotiations as a way to end the stand-off.
The US envoy for Venezuela, Elliott Abrams, said in Washington that Mr Maduro had presided over economic decline and human rights violations in Venezuela.
“In every democratic transition in Latin America there are negotiations, but I just would say it is extremely difficult to see how he could play a positive role in a democratic election,” Mr Abrams said.
The United States and some 50 other countries have recognised Mr Guaido as the legitimate leader of Venezuela and have urged Mr Maduro, who is backed by Russia, to resign so the country can prepare for elections.