The decision also comes amid growing concern that American diplomats could become a pawn in the battle with President Nicolas Maduro as the U.S. tries to push him from power.
But the sudden reversal was announced late Monday night in a statement where Pompeo called embassy staff's presence a "constraint on U.S. policy."
"Decisions you make are always encumbered by the fact that you know there's real risk to your own people, people that you've sent into harm's way," Pompeo added Tuesday. "We wanted to get them out of the country so that we could move forward in a way that provided that opportunity."
U.S. Special Envoy for Venezuela Elliott Abrams wouldn't say what had been constrained, but that diplomats' presence weighed on senior officials in Washington because the U.S. does not believe Maduro's government had the ability to protect them.
Since recognizing Guaido, the U.S. has sanctioned the state-owned oil company and top Maduro-aligned officials, imposed visa bans or revocations on over 250 officials and amassed around 200 metric tons of humanitarian aid across the border in Colombia and supported efforts by Guaido and his supporters to rush it across the border.
But nearly two months after casting Maduro as no longer legitimate, the socialist leader remains in control, backed by allies Cuba and Russia. Top Trump officials have warned in recent days that they want to take action to accelerate Maduro's departure, with Abrams saying Tuesday that there will be a "significant number of additional visa revocations" and "some very significant additional sanctions" imminently.
That could have exposed U.S. diplomats to retaliatory action by Maduro's government, especially as it grows more desperate amid the declining humanitarian situation.
"In every decision we made ... the safety of that staff was a key consideration, and that was something that weighed very heavily on our mind," Abrams told reporters Tuesday.
The embassy's facilities were also facing "a finite number of days" because of fuel shortages, a lack of water access, and little to no electricity and, therefore, telecommunications, Abrams said.
Venezuela has been left in darkness, for five days now, with power outages across the country that have been blamed for deaths at hospitals and water and food shortages. Maduro's government has accused the U.S. of being behind the blackouts, which Pompeo denied Monday, calling them "a direct result of years and years of neglect to the Venezuelan energy system."
Maduro's Foreign Minister Jorge Arreaza said Tuesday that they were behind the departure of remaining U.S. diplomats, ordering them to leave after talks over their continued presence broke down Monday.
Abrams confirmed that there had been talks with the Maduro government about U.S. diplomats, but because the U.S. viewed him as the "former" president of the country, his government had no right to expel Americans, who remained at the request of Guaido. While the U.S. remains confident in Guaido and his fledgling government, Abrams added, "The fact is that today, the regime has the guns."
The embassy had previously ordered the departure of non-emergency personnel and families in late January, slimming a staff of 100 to 150 personnel down to just a handful, led by Chargé d' Affaires Jimmy Story. U.S. personnel will depart over the next couple of days, although the State Department has declined to say when that process will begin or end.
That means no U.S. government services for the remaining American citizens, who at one time numbered between 30,000 and 40,000, according to Special Representative for Venezuela Elliott Abrams. That number has likely decreased as the economic crisis has deepened in recent weeks, a State Department official told ABC News.
The State Department lists Venezuela as a "Level 4: Do Not Travel" on its advisory, urging American citizens to evacuate. The U.S. is in talks with a handful of countries to designate a protecting power -- a third-party nation that looks after U.S. citizens in a foreign country, like Sweden does in North Korea.
But even before a protecting power has been designated, the U.S. will not provide evacuations for U.S. citizens, urging them instead to leave as soon as possible on commercial travel.