Venezuela has told international airlines to resume flights to the country within 48 hours or risk being stripped of their clearance to fly there altogether.

Several airlines suspended their flights to Venezuela after the US aviation regulator warned on Friday of "heightened military activity" in the area.

The warning came as the US ramped up pressure on the Venezuelan government, sending the world's largest aircraft carrier to the southern Caribbean as part of a larger military build-up.

The International Air Transport Association (IATA) has warned Venezuela's aviation authority that rescinding airlines' clearance would only isolate the country further.

Venezuela's aviation authority (Inac), which reports to the country's ministry of transport, issued the ultimatum on Monday.

Among the airlines affected are Spain's Iberia, Air Europa and Plus Ultra, Brazil's Gol, Chile's Latam, Colombia's Avianca, Portugal's TAP and Turkish Airlines.

All of them - except Trinidad and Tobago's Caribbean Airlines, which had already stopped flights in September - halted their flights to Venezuela after the US Federal Aviation Administration (FAA) issued a "Notice to Air Missions" on Friday.

In it, the FAA advised flight operators "to exercise caution when operating in the Maiquetía flight information region at all altitudes due to the worsening security situation and heightened military activity in and around Venezuela".

Maiquetía is the location of Venezuela's main international airport, serving the capital, Caracas.

While a number of airlines, including Panama's Copa and Venezuela's state-owned Conviasa, have continued to fly in and out of Maiquetía, the suspensions have severely curtailed the number of international flights.

Aviation industry body Iata urged Inac to drop the deadline, to avoid further reducing "connectivity to the country, which is already one of the least connected in the region".

Iata stressed in a statement that its member airlines had suspended their flights temporarily and remained "committed to restoring operations to and from Venezuela as soon as conditions allow".

Tension between the US and Venezuela has been growing since the former escalated its military presence in the southern Caribbean, in an operation it says is designed to combat drug trafficking.

The US Navy has carried out at least 21 strikes against boats allegedly carrying drugs - mostly in the Caribbean but also a few in the Pacific - since the beginning of September.

The Venezuelan president, Nicolás Maduro, has denounced the strikes and the military build-up, accusing the US of trying to overthrow him.

On Monday, he struck a defiant note telling viewers of his TV show that "they [the US] will not be able to defeat Venezuela, we are invincible".

The US government has labelled Maduro as an illegitimate leader, pointing to his 2024 re-election, which was widely dismissed as rigged.

However, US President Donald Trump has not ruled out speaking directly to Maduro, telling reporters last week that "at a certain period of time, I'll be talking to him".