President Donald Trump said Wednesday that U.S. forces had seized a “very large” oil tanker off the coast of Venezuela, a major move against the South American country.

“As you probably know, we have just seized a tanker on the coast of Venezuela, a large tanker, very large, the largest one ever seized actually,” Trump said at an event at the White House.

The White House did not provide additional details about the vessel. A person familiar with the matter, granted anonymity to discuss the sensitive seizure, said the ship was en route to Cuba. The oil, the person said, would be sold by state firm Cubametales to Asian energy brokers.

The Cuban Embassy in Washington did not immediately respond to a request for comment.

It’s a major escalation of the pressure campaign the U.S. has waged against Venezuela. The Trump administration has restored tough sanctions against the South American petrostate and built up military presence in the Caribbean in an effort to pressure Venezuelan leader Nicolás Maduro to cede power to the opposition.