The United States has seized a sanctioned Venezuelan oil tanker off the country’s coast, President Donald Trump announced, marking the first known tanker seizure since the recent U.S. military buildup in the region.

Axar.az, citing Reuters, reports that the move sharply escalates tensions with Caracas and pushed oil prices higher. Venezuela condemned the action as “international piracy” and vowed to take the case to global bodies.

The tanker, identified by maritime analysts as the VLCC Skipper, had loaded 1.8 million barrels of Merey crude at Venezuela’s Jose terminal and partially transferred some cargo before the seizure.

U.S. agencies, including the FBI, Homeland Security, and Coast Guard, conducted the operation with military support. The ship had previously been sanctioned for involvement in Iranian oil trading and was found to be falsely flying Guyana’s flag.

Oil futures rose slightly after the news.