Pompeo was gone by the time Foreign Minister Jorge Arreaza took the floor to accuse the USA of trying to "trigger a civil war" in Venezuela and listed nearly two centuries of US interventions in the region going back to the Monroe Doctrine in 1823.
"The internal situation of this Latin American country should not be on the agenda".
The ultimatum comes as global pressure mounts on the Maduro regime to agree a new vote, with the United States, Canada and major South American players already recognising Guaido, who proclaimed himself acting president of Venezuela during massive street rallies this week.
European Union foreign policy chief Federica Mogherini reiterated Brussels' call for Venezuela to hold free, transparent and credible presidential elections, adding that failure to do so would prompt further action by the EU. The young opposition leader has declared himself the country's interim president, arguing that Maduro's re-election was fraudulent.
In heated back-and-forth exchanges at a United Nations Security Council meeting, the opposing camp led by Venezuela and Russian Federation, which has invested heavily in Venezuela's oil industry, accused Washington of attempting a coup, and lambasted Europeans' demand that elections be called within eight days.
Spain is closely linked to Venezuela, a former colony, as some 200,000 of its nationals live there.
"Either you stand with the forces of freedom, or you're in league with Maduro and his mayhem", Pompeo said at an emergency meeting of the 15-member U.N. Security Council Saturday called by the United States.
But Venezuela quickly rejected the ultimatum delivered by the leaders of the United Kingdom (UK), Spain, Germany and France.
Also on Twitter, German government spokeswoman Martina Fietz used almost identical language, adding "complete security" as a necessary condition for elections.
Venezuelan armed groups loyal to Maduro have clashed with protesters supporting Guaido, leaving at least 20 people dead and many wounded, the United Nations human rights office said Friday.
"@jguaido is the right person to take Venezuela forward", he said in a tweet.
"If that doesn't happen, Spain will recognize Juan Guaido as interim president in charge of calling these elections".
"Time for a new start for the suffering ppl (people) of Venezuela".
After Washington's declaration of support for Guaido, Maduro cut off diplomatic relations with the United States on Wednesday and gave US diplomats 72 hours to leave the country.
"The people of Venezuela must be able to freely and securely decide about its future", Merkel said, according to the Associated Press.
Portugal joined its fellow European Union members' call, saying that one week was "an appropriate timeframe" for Maduro to announce fresh elections.
Speaking from his office in the Venezuelan Embassy in Washington, Silva called for free and fair elections to take place in Venezuela.
But he saved his sharpest attack for Cuba, saying no country has done more to sustain "the nightmarish condition of the Venezuelan people".
Greece's ruling party Syriza has publicly backed him, with party secretary Panos Skourletis voicing "full support and solidarity" to what to he called "the legal president".