The warning came amid reports of armed militias.
Deposed Venezuelan President Nicolás Maduro and his wife appeared in a federal court in New York City on Monday, following their capture by U.S. forces over the weekend in a military operation in the Venezuelan capital of Caracas.
Following the operation, President Donald Trump said that the U.S. would "run" Venezuela for an unspecified "period of time."
Venezuelan Vice President Delcy Rodriguez has been sworn in as interim leader to lead the country after what the Venezuelan Supreme Court described as Maduro's "kidnapping."
Maduro is expected to arrive at the U.S. military base in Guantanamo Bay before being transferred to an FBI plane en route to New York, sources familiar with the matter told ABC News.
-ABC News' Pierre Thomas, Sam Sweeney and Katherine Faulders
A source familiar with the operation told ABC News that the CIA "had a small team clandestinely on the ground starting in August that was able to provide extraordinary insight into Maduro’s pattern of life that made grabbing him seamless."
CIA Director Ratcliffe, along with Stephen Miller, Rubio and Hegseth, "formed a core team working this issue for months with consistent meetings and phone calls, sometimes even daily … often meeting both with the president and separately," according to the source.
-ABC News' Cindy Smith
Venezuela opposition leader Maria Corina Machado issued a statement on Saturday, calling on all Venezuelans to "be ready to mobilize what we will soon communicate to you through our official channels."
She called on the military to recognize opposition leader Edmundo González Urrutia, who ran against Maduro in the last election, as the rightful president of Venezuela.
"Venezuelans, the hour of freedom has arrived," she wrote. "As of today, Nicolás Maduro, will face international justice for the atrocious crimes committed against Venezuelans and against citizens of many other nations. Due to his refusal to accept a negotiated exit, the government of the United States has fulfilled its promise to uphold the rule of law."
Machado continued, "Today we are ready to take over power. We remain vigilant, active, and organized until a democratic transition is concrete. A transition that needs ALL of us."
Machado also called on Venezuelans abroad to mobilize and help build "the new Venezuela."
-ABC News' Victoria Moll Ramirez
Sen. Tim Kaine, one of the Senate's most vocal advocates for Congressional war authorizations, issued a scathing statement of President Trump's actions in Venezuela and called for Congress to take up his resolution that would block the use of the U.S. Armed Forces to engage in hostilities within or against Venezuela unless authorized by Congress.
"Where will this go next? Will the President deploy our troops to protect Iranian protesters? To enforce the fragile ceasefire in Gaza? To battle terrorists in Nigeria? To seize Greenland or the Panama Canal? To suppress Americans peacefully assembling to protest his policies? Trump has threatened to do all this and more and sees no need to seek legal authorization from people’s elected legislature before putting servicemembers at risk," the Virginia Democrat said in his statement.
-ABC News' Allison Pecorin
