Venezuela later allowed a skeletal staff to remain at the hilltop U.S. Embassy until Thursday's withdrawal.
The giant USA flag was lowered at the sprawling hillside embassy shortly before the roughly 20 diplomatic personnel left for the airport Thursday morning.
The OPEC nation suffered its worst blackout in history last week following technical problems that the government of President Nicolas Maduro called an act of USA -backed sabotage but critics dismissed as the result of incompetence.
As Venezuela's power finally comes back online and its people return to work, US Secretary of State Mike Pompeo announced "the American people are with" the beleaguered Venezuelans, blaming "the Maduro regime" for denying them access to food, medicine, and - of course - democracy.
Pompeo released a statement Thursday, soon after the last diplomats were reported to have left. "US diplomats will now continue that mission from other locations where they will continue to help manage the flow of humanitarian assistance to the Venezuelan people and support the democratic actors bravely resisting tyranny".
"I know it is a hard moment for them", he said, referencing the US diplomats.
The latest revocations - which include visas for 107 former diplomats and their families - brings the total to more than 600 since late 2018, spokesman Robert Palladino said. Palladino urged any US citizens left in Venezuela to leave.
He gave no details
An employee uses his mobile phone torch to help a customer on 10 March 2019, during the third day of a massive power outage which has left Venezuelans without communications, electricity and water.
"This I'm afraid can only be clarified and explained by the party accused by President Maduro", Lu said.
Maduro blamed the blackouts on alleged sabotage engineered by the US and the Venezuelan opposition.
Venezuela's pro-Maduro prosecutor's office has hit back with a criminal investigation against Guaido for "sabotage", alleging he had a hand in the blackout. USA officials and Guaido said the allegation is absurd and that government corruption and mismanagement caused the infrastructure collapse in a country already suffering hyperinflation and shortages of basic goods.
That move has put Venezuela at the heart of a geopolitical tussle, with the United States leading most Western nations in recognizing Guaido as the legitimate head of state, while Russia, China and others support Maduro.