Juan Guaido, Venezuela's self-proclaimed president, says a staggered industrial action would start Thursday, leading to a general strike.

The strike is the latest strategy in his effort to force President Nicolas Maduro out of power through a popular uprising. Two days of rallies in the streets of Caracas have led to violent clashes between Guaido's supporters and Venezuelan forces, but the military's top officers have yet to heed Guaido's call to defect from Maduro.

Millions of Venezuelans fed up with out-of-control inflation, severe food and fuel shortages, a lack of medical care, and periodic blackouts have fled the country.

As head of the opposition-controlled National Assembly, Guaido used the constitution to declare Nicolas Maduro's presidency illegitimate, saying his election in December was a fraud. He has been recognized by the United States and more than 50 other nations as Venezuelas rightful president.

Maduro is accusing Guaido of trying to carry out a U.S.- and Colombian-supported coup and says the opposition will fail.

He said demonstrators will be prosecuted 'for the serious crimes that have been committed against the constitution, the rule of law and the right to peace.'

Wednesday's confrontations between opposition supporters and Venezuelan troops ended with one woman dead after she was shot in the head during a protest in the capital.

Meanwhile, the unrest in Venezuela is turning into a battleground of rhetoric between the United States and Russia.

After a telephone conversation between Secretary of State Mike Pompeo and Foreign Minister Sergey Lavrov Wednesday, the Russian foreign minister warned of 'the most drastic of consequences' if the United States continues what it calls 'aggressive steps.'

The State Department was more muted, only saying that Russian and Cuban intervention is 'destabilizing for Venezuela.'

But U.S. National Security Advisor John Bolton said, 'This is our hemisphere. It's not where the Russians ought to be interfering. This is a mistake on their part. It's not going to lead to an improvement of relations.'

Pompeo said again Wednesday the United States is prepared to use military action in Venezuela 'if that is what is required, this is what the United States will do.'

But Pompeo, and President Donald Trump, have not specified what would prompt the U.S. to intervene militarily.

Meanwhile, a top Cuban diplomat has denied U.S. accusations that thousands of Cuban troops are on the ground in Venezuela.

'Cuba does not participate in military operations nor in security operations in Venezuela,' Cuban chief of U.S. Affairs Carlos Fernandez de Cossio told the Associated Press.

He said the 20,000 Cubans in Venezuela are primarily medical workers.

But he did say, as hemispheric partners, Cuba and Venezuela have the sovereign right to military and intelligence cooperation.

Cuba and Russia are longtime allies of Venezuela and its socialist governments. Russia has supplied economic support and military equipment to the Maduro government while Venezuela has sent billions of dollars in oil to Cuba in exchange for medical aid.