United States Secretary of State Marco Rubio has said that military attacks on alleged drug traffickers will “happen again”, brushing aside concerns over the legality of such attacks and the sovereignty of Latin American nations.

Speaking during a news conference in Mexico City on Wednesday, Rubio pledged continued security coordination with countries like Mexico, but suggested the US would not hesitate to take extreme measures on its own.

His remarks, in part, were a response to President Donald Trump’s announcement that the US had blown up a vessel in the Caribbean Sea a day earlier.

Trump and Rubio identified the small boat as a drug-smuggling vessel coming from Venezuela, though no details were provided. All 11 people on board reportedly died.

Rubio framed the air strike as part of a shifting strategy in the US’s ongoing “war on drugs”.

“The United States has long — for many, many years — established intelligence that allowed us to interdict and stop drug boats. And we did that. And it doesn’t work. Interdiction doesn’t work,” Rubio said.

“What will stop them is when you blow them up, when you get rid of them.”

Rubio then explained that the strike was authorised personally by Trump. The boat had been in the south Caribbean Sea at the time of the attack, and Rubio said it was headed for the US.

“Instead of interdicting it, on the president’s orders, we blew it up. And it will happen again,” Rubio said. “Maybe it’s happening right now. I don’t know.”

Rubio’s visit to Mexico City comes as the Trump administration seeks close cooperation with Mexico, but its aggressive foreign policy has spurred concerns abroad.

Latin American nations have struggled to balance the need for working relations with the US and Trump’s increasingly brazen threats.

Experts say that attacks like Tuesday’s boat bombing are likely illegal under international law, which limits military actions on vessels sailing through international waters.

Still, Rubio defended the action as necessary for protecting the wellbeing of the US.

“If you’re on a boat full of cocaine or fentanyl, whatever, headed to the United States, you’re an immediate threat to the United States,” said Rubio.

US military strikes against armed groups around the world have often depended on the idea that such groups, often tied to armed or fighting groups that represent an immediate risk to US national security. That argument has not previously been used as a pretext for military strikes on drug trafficking, deemed a criminal issue.

But Trump’s second inauguration has marked a shift in that approach.

Since taking office in January, Trump has pushed for emergency powers on the premise that Latin American gangs and other criminal groups constitute an “invasion” on US soil.

He has also designated many such groups as “foreign terrorist organisations”.

In August, reports emerged that Trump had signed an order authorising military strikes against cartels and other drug-smuggling operations, fuelling fears that the US would carry out military strikes in Latin America despite concerns about sovereignty.

Such concerns have been particularly prominent in Mexico, the US’s immediate neighbour to the south.

To mark Rubio’s visit, Mexico and the US issued a joint statement emphasising “respect for sovereignty and territorial integrity”.

Mexican President Claudia Sheinbaum has also repeatedly sought to dispel worries that the Trump administration may take unilateral action on Mexican soil. Trump, meanwhile, has not ruled out such a possibility.

Al Jazeera correspondent John Holman explained that Rubio’s visit was aimed at “smoothing the feathers” and lowering tensions in Mexico.

“There was a lot of fulsome praise. But the elephant in the room here really is that President Trump has been saying repeatedly that, if Mexico wants it, then the US is very happy to send its military down into the country to fight drug cartels,” Holman explained.

“That really wasn’t touched on in this meeting apart from the Mexican foreign minister repeatedly saying that, ‘Yes, we’re going to work with the United States’ — in a very diplomatic way, saying everyone in their own jurisdiction.”

Nevertheless, Rubio and other US officials have emphasised that the US would continue to collaborate on security and drug enforcement with Mexico, which the US has pushed to take a more aggressive stance.

“We’ve got assets in the air, assets in the water, assets on ships, because this is a deadly serious mission for us, and it won’t stop with just this strike,” Defense Secretary Pete Hegseth said on the TV show Fox and Friends.

Not all countries in the region are apprehensive as the US takes on an increasingly militarised approach to criminal groups.

“I, along with most of the country, am happy that the US naval deployment is having success in their mission,” Trinidad and Tobago’s Prime Minister Kamla Persad-Bissessar said in a statement on Tuesday.

“The pain and suffering the cartels have inflicted on our nation is immense. I have no sympathy for traffickers; the US military should kill them all violently.”