Guaido told supporters at the rally in Caracas that the support of the army was "fundamental" to oust Maduro, "but time is passing and the wait cannot be eternal." 

He reminded military leaders they have "a historic opportunity resting on their shoulders." 

Despite support from more than 50 states who recognise him as interim president, US-backed Guaido has been unable to affect Maduro's grip on the military, which continues to keep him in power, along with allies China and Russia.

Guaido will aim to keep up the street pressure on the regime with a huge Mayday protest on Wednesday that he said would be "the largest in the country's history." 

At his rally on Saturday, he held a swearing-in ceremony for "freedom commandos" -- volunteers he has put in charge of organising ongoing protests against the government.