Ecuador has released the survivor of a US strike on a submarine alleged to have been smuggling drugs in the Caribbean.

US military forces captured the Ecuadorean national along with a Colombian citizen after they attacked the submarine the two were on. US President Donald Trump said they would be returned to their countries of origin for detention and prosecution.

However, the Ecuadorean Attorney General's office stated that the survivor could not be detained due to the lack of a reported crime brought to their attention.

The US has conducted a series of strikes on what it describes as drug-smuggling vessels in the region, with recent operations aimed at halting narcotics trafficking.

Ecuadorian officials earlier identified one survivor as Andrés Fernando Tufiño. They and Colombian man Jeison Obando Pérez are the first two survivors of the US attacks, which have killed at least 32 individuals since September.

Experts have raised questions regarding the legality of the strikes, suggesting potential breaches of international law, while the Trump administration insists they target narco-terrorists.

At a White House press briefing, Trump described the men aboard the submarine as not innocent, asserting they were involved in drug trafficking operations.

A significant US military presence in the Caribbean, estimated around 10,000 troops, has been noted, with operations mainly targeting vessels departing from Venezuela amid accusations directed at Venezuelan President Nicolás Maduro.

Meanwhile, the two survivors were rescued and taken to a US warship for repatriation, with the Ecuadorean survivor reported to be in good health. In contrast, the Colombian survivor is receiving treatment for serious injuries sustained in the attack.

This situation highlights an ongoing humanitarian and legal dilemma surrounding the US's aggressive counter-narcotics strategy in the region.