Guaido called for a series of escalating workers' strikes to begin on Thursday which he said would culminate in a general strike that would force Maduro from power.

The opposition leader urged government workers to join political protesters on the streets, while insisting in an interview with Fox Business that Venezuela is "very close to achieving freedom... as long as we remain united".

But there are signs that Guaido's bid for power is grinding to a halt after a "military uprising" that he declared on Tuesday largely failed to materialise, with most senior defence chiefs remaining loyal to Maduro.

The call to arms did provoke protests across the country but these quickly descended into scatter-gun violence, with at least two dead and more than 100 wounded so far.

Meanwhile, relations between America, which backs Guaido, and Russia, which supports Maduro, soured as each accused the other of interfering in another country's affairs. 

It was unclear what more Guaido can do. The Venezuelan opposition has often staged huge street protests against Maduro but failed to dislodge him despite a deep economic recession and hyperinflation.

Demonstrators said they were prepared for the process of ousting Maduro to last a long time.

"We need to keep going," said Laila Amezquita, a 52-year-old nurse from Caracas, downtown Candelaria district.

"In three months Guaido's been able to do what they have not done in 20 years, and one has to be patient."

Others are frustrated that nothing has changed more than three months after Guaido, head of the opposition-run National Assembly, invoked the constitution to assume an interim presidency, arguing that Maduro's 2018 re-election was illegitimate.

Guaido is recognized as Venezuela's legitimate head of state by the United States, the European Union and others, while Maduro is backed by countries including Russia, China, and Cuba. 

Those fault lines are increasingly putting Venezuela at the heart of global geopolitical tensions.

U.S. Secretary of State, Mike Pompeo, said Maduro had been expected to flee the country on Tuesday but Russia convinced him to stay, which the Kremlin has denied.

White House national security adviser John Bolton, a foreign policy hawk, said Moscow's involvement was not welcome.

"This is our hemisphere," he told reporters outside the White House. "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."

Maduro retains control of state institutions and the loyalty of the armed forces, frustrating Guaido's bid to assume the day-to-day functions of government, which he says would be a prelude to calling new elections.

Seeking to appeal to Maduro's traditional base among the working class, Guaido said on Wednesday he would consider a proposal from public workers to call for a series of stoppages leading up to a general strike.

Venezuelan living standards have declined even further in the first several months of the year, with blackouts and water shortages adding to hyperinflation and chronic shortages of food and medicine that have prompted millions to emigrate.

Triple the usual daily number of Venezuelans fled across the border to Brazil on Tuesday, Brazilian government data showed.

Maduro, who says Guaido is a puppet of the United States seeking to orchestrate a coup, also called a march on Wednesday.

In a speech to supporters gathered near the Miraflores presidential palace, Maduro said he recognised the need for "big changes within the Bolivarian revolution". He did not give details.

Travelling to the pro-Maduro rally, educator Mercedes Martinez called Guaido a "lapdog" and said: "The empire wants to smother us, cut off our head and colonize us. ... The people of Venezuela are defending Venezuela."

Daily Mail