Venezuela's opposition has called a daylong general strike for Thursday, hoping to pressure President Nicolas Maduro into calling off plans for a new constitution.
The opposition is launching what it says is a "final offensive" on Maduro to call for early presidential elections.
In a nonbinding national referendum Sunday organized by opposition groups, more than 7 million Venezuelans — nearly one-third of the national electorate — called on Maduro to give up the idea of electing a special assembly to put together a new constitution.
President Donald Trump said late Monday the United States will take "strong and swift economic actions" if Maduro goes through with his plans.
"The Venezuelan people again made clear that they stand for democracy, freedom and the rule of law," the U.S. president said in a statement. "Yet their strong and courageous actions continue to be ignored by a bad leader who dreams of becoming a dictator."
Maduro brushes off opposition
Maduro called the opposition referendum illegal and is continuing to push ahead with plans for a July 30 vote for the special assembly.
Changing the constitution is the only way to pull Venezuela out of its deep economic and social crisis, the president said.
"I'm calling on the opposition to return to peace, to respect the constitution, to sit and talk," he said Sunday. "Let's start a new round of talks, of dialogue for peace."
The opposition says the assembly will be rigged in Maduro's favor. It says rewriting the constitution is nothing but a Maduro ploy to dissolve state institutions and turn Venezuela into a socialist dictatorship, leaving the opposition-led national Assembly irrelevant.
Shortages in shops and lack of rights
One voter who rejects the idea of a new constitution told The Associated Press: "There's no medicine, no food, no security. ... No separation of powers, no freedom of expression."
Lower global energy prices and government corruption have destroyed Venezuela's once-thriving economy, which is dependent on oil revenues.
Consumers face severe shortages of basic goods such as gasoline, flour, sugar and cooking oil. Supermarket shelves are bare and many Venezuelans cross into neighboring Brazil and Colombia to buy food.
Daily street protests against the government frequently blow up into violence. Nearly 100 people have been killed over the last three months.
Maduro blames his country's woes on what he calls U.S. imperialism. He warns against intervention by the Organization of American States, saying that would surely bring on civil war.