FOZ DO IGUAÇU, Brazil (AFP)—Brazilian President Luiz Inacio Lula da Silva said Saturday that US military action in Venezuela would spark a “humanitarian catastrophe,” as he opened a summit of the South American Mercosur bloc.

Lula’s comments come amid spiraling tensions between Washington and Caracas — and after US President Donald Trump left open the possibility of war against the government of Venezuelan strongman Nicolas Maduro.

The US military has beefed up its presence in the Caribbean in recent months and carried out air strikes against alleged drug boats in the region and in the Pacific, claiming that it is combatting narcotics trafficking.

But Maduro says the campaign is part of a wider effort to carry out regime change in Caracas.

“Four decades after the Falklands war, the South American continent is once again haunted by the military presence” of a foreign power, Lula said in the southern city of Foz do Iguacu, referring to the 1982 UK-Argentina conflict over disputed islands in the South Atlantic.

“An armed intervention in Venezuela would be a humanitarian catastrophe for the hemisphere and a dangerous precedent for the world,” he said.

In an interview with NBC News conducted Thursday, when asked about the potential for war, Trump replied: “I don’t rule it out, no.”

On Thursday, Lula said he was “very worried” about the mounting crisis on Brazil’s doorstep and was prepared to serve as a mediator to avert armed conflict.

The 80-year-old leftist said he had told Trump that “things wouldn’t be resolved by shooting, that it was better to sit down around a table to find a solution.”

At least 104 people have been killed in the US strikes on alleged drug boats, though the Trump administration has not yet provided any concrete evidence that the boats it has targeted were ferrying drugs.

The US government has accused Maduro of leading the “Cartel of the Suns” — a charge he denies.

Trump has also announced a blockade on oil tankers under sanctions that are leaving or arriving in Venezuela.