The Trump administration has intensified its efforts against Venezuelan leader Nicolás Maduro, who faces narcoterrorism charges in the United States.

“We’ve just seized a tanker off the coast of Venezuela, a massive one—the largest ever seized, in fact,” President Trump announced to reporters at the White House.

While hinting at further actions, Trump refrained from providing more specifics, promising to disclose additional information at a later time.

The operation to seize the tanker was executed by the US Coast Guard with support from the Navy, according to a US official who requested anonymity as they were not authorized to speak publicly.

In a related move, the US military dispatched two fighter jets over the Gulf of Venezuela, marking one of the closest approaches to Venezuelan airspace since the Trump administration began its campaign to apply pressure on the South American nation.

The US 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.

Trump has said land attacks are coming soon but has not offered any details on location.

Among the concessions the US has made to Maduro during past negotiations was approval for oil giant Chevron Corp to resume pumping and exporting Venezuelan oil. The corporation’s activities in the South American country resulted in a financial lifeline for Maduro’s government.