President Trump on Saturday declared that the airspace over and around Venezuela is deemed “closed in its entirety,” escalating tensions as he signals potential military action against the South American nation.

In a post on his Truth Social platform, Mr. Trump addressed a wide audience with the directive: “To all Airlines, Pilots, Drug Dealers, and Human Traffickers, please consider THE AIRSPACE ABOVE AND SURROUNDING VENEZUELA TO BE CLOSED IN ITS ENTIRETY.”

The declaration follows Mr. Trump’s threats to expand U.S. military operations, which have so far focused on maritime strikes in the Caribbean, to targets on Venezuelan soil “very soon.”

The administration has justified its actions as a crackdown on extensive drug trafficking networks, though the threats have often been linked to a broader effort to depose President Nicolás Maduro, whom the American government has long deemed an illegitimate leader.

During a Thanksgiving call with American service members on Thursday, Mr. Trump suggested that strikes within Venezuela are imminent.

“In recent weeks, you’ve been working to deter Venezuelan drug traffickers, of which there are many,” he said. “You probably noticed that people aren’t wanting to be delivering by sea, and we’ll be starting to stop them by land also … the land is easier, but that’s going to start very soon.”

Since early September, America has conducted at least 20 strikes against boats in the Caribbean, claiming they were operated by drug cartels. According to the administration, the  operations have resulted in at least 83 deaths.

Despite Mr. Trump’s unilateral declaration, Venezuela maintains sovereign control over its airspace. Flight-tracking data on Saturday morning showed a handful of aircraft still operating over the country. There was no immediate official response from the Venezuelan government.

The situation has prompted caution from aviation authorities. Last week, the Federal Aviation Administration advised airlines to “exercise caution” over Venezuela due to the “worsening security situation and heightened military activity.”

In response, Venezuela’s civil aviation authority on Wednesday revoked landing and takeoff rights for six commercial carriers, accusing them of “joining the actions of state terrorism promoted by the United States government.”

This military posturing coincides with a significant buildup of U.S. forces in the region. The Pentagon recently deployed 10 F-35 fighter jets to Puerto Rico, and the USS Gerald R. Ford, one of the world’s most advanced aircraft carriers, has joined eight other warships and some 10,000 troops. Mr. Trump has also reportedly authorized the CIA to conduct covert operations in Venezuela, a move Mr. Maduro called a “desperate” attempt at regime change.

Legal experts and analysts have raised questions about the legality of the American strikes, which have been carried out without congressional approval.

The Trump administration has also intensified its diplomatic and economic pressure on Mr. Maduro. Mr. Trump has accused the Venezuelan leader of heading the Tren de Aragua organized crime gang and being responsible for trafficking fentanyl to America.

Last week, America designated the Cartel de los Soles, a group Washington alleges Mr. Maduro runs, as a foreign terrorist organization. The reward for information leading to Mr. Maduro’s arrest was increased to $50 million in August.

Amid the escalating rhetoric, there have been tentative signs of a diplomatic thaw. The New York Times reported Friday that Mr. Trump and Mr. Maduro spoke last week about a potential meeting, which would mark the first between the Venezuelan leader and an American president.