Caracas - A 24-hour nationwide strike in Venezuela on Thursday is set to increase pressure on beleaguered President Nicolas Maduro, whose policies have put him on a collision course with the United States.The opposition called the stoppage after holding an unofficial plebiscite last weekend in which a third of Venezuela's voters cast ballots rejecting Maduro and his policies.Chief among them is the president's plan to hold an election July 30 to choose a 545-member citizens' body, called a Constituent Assembly, to rewrite the constitution.US President Donald Trump has threatened "swift economic actions" against Venezuela if that election happens.The European Union, the United Nations, the Organization of American States and the Catholic Church have all condemned Maduro's plan.They fear the move - seen by the opposition and Trump as a bid for dictatorship - will irretrievably worsen the political crisis in Venezuela, and risk adding to a death toll that currently stands at 97 since anti-Maduro street protests turned violent in April.'Final offensive'But Maduro has vowed to forge on "now more than ever" after Trump's threat, and to punish "conspirators" who try to stop him.His labor minister, Nestor Ovalles, warned that companies in Venezuela that joined the strike on Thursday would be "sanctioned."And the military reaffirmed its loyalty to Maduro by saying it would protect the polling.The opposition, which controls the National Assembly, sees the strike as the launch of a "final offensive" including civil disobedience and further protests designed to force Maduro out of office through early elections.Previous efforts to bring about a recall referendum against Maduro were stymied by electoral authorities and judges who have systematically sided with the president.With efforts at negotiations between both sides also exhausted, the stalemate risks worsening the deteriorating situation ordinary Venezuelans are enduring.Their oil-rich nation is staggering under a lack of food and medicine, triple-digit inflation, rising crime and dire currency controls that enrich a few at the expense of the many.Maduro has blamed the crisis on low global oil prices and an economic "war" waged on him by the United States and the right-wing opposition.But the opposition says the crisis is due to government mismanagement, including nationalizations and state appropriations of firms, and generally inept policies by Maduro and his late predecessor Hugo Chavez.US sanctions 'effective'?It's not clear what "actions" Trump is considering against Venezuela, but oil could be a key pressure point. Around a third of Venezuela's crude production is exported to the US market."All options are on the table," a senior White House official said Tuesday.But Geoff Thale, with the Washington Office on Latin America (WOLA) lobbying group, told AFP he was "very skeptical that unilateral US sanctions (would be) effective.""They are more likely to make the government feel they have no option but to resist, and they offer the government a nationalist rallying cry against the US," he said.