The oil tanker seized by the United States off the coast of Venezuela will be taken to a U.S. port, White House press secretary Karoline Leavitt said Thursday.

The tanker is a "sanctioned shadow vessel known for carrying black-market sanctioned oil to the IRGC [Islamic Revolutionary Guard Corps]" and will be taken to a U.S. port, Leavitt told reporters during a news briefing.

Using U.S. forces to seize an oil tanker is unusual and marks the Trump administration's latest push to increase pressure on Venezuelan President Nicolas Maduro, who has been charged with narcoterrorism-related offenses in the United States.

The U.S. has built up the largest military presence in the region in decades and launched a series of deadly strikes on alleged drug-smuggling boats in the Caribbean Sea and eastern Pacific Ocean.

The seizure Wednesday was led by the U.S. Coast Guard and supported by the Navy, according to a U.S. official who was not authorized to comment publicly and spoke on the condition of anonymity. The official added that the seizure was conducted under U.S. law enforcement authority.

Venezuela has the world's largest proven oil reserves and produces about 1 million barrels a day. Locked out of global oil markets by U.S. sanctions, the state-owned oil company sells most of its output at a steep discount to refiners in China.

Venezuela's government has accused the U.S. of "international piracy," and says its "objective has always been to seize Venezuelan oil without paying any compensation."

Leavitt said the vessel is currently undergoing a forfeiture process.

“Right now, the United States currently has a full investigative team on the ground, on the vessel, and individuals on board the vessel are being interviewed, and any relevant evidence is being seized with respect to the oil, that's a different issue," she said.

"As you know, the vessel will go to a U.S. port, and the United States does intend to seize the oil. However, there is a legal process for the seizure of that oil, and that legal process will be followed."

The Associated Press contributed to this report.