In a significant development off the coast of Venezuela, U.S. forces intercepted a vessel on Saturday, marking the second such occurrence in less than two weeks. This action underscores President Donald Trump’s escalating efforts to pressure Venezuelan President Nicolás Maduro.

The interception, confirmed by two U.S. officials who requested anonymity due to the sensitivity of the ongoing military operations, follows a recent announcement by Trump. He declared a “blockade” on all sanctioned oil tankers entering or leaving Venezuela. This latest intervention comes shortly after American forces seized an oil tanker near the Venezuelan coast on December 10.

According to one official, the intervention was a “consented boarding,” where the tanker voluntarily halted and permitted U.S. forces to come aboard. However, the Pentagon and White House have yet to issue any public statements regarding this operation.

Earlier this month, following the initial tanker seizure, Trump asserted that the U.S. would enforce a blockade on Venezuela. His rhetoric against Maduro has grown increasingly severe, with the U.S. President asserting that Maduro’s tenure is nearing its end.

Adding to the tension, Trump recently called for Venezuela to return assets seized from U.S. oil companies years ago. This demand reinforces his rationale for implementing a blockade on oil tankers associated with Venezuela that are subject to American sanctions.

Trump this week demanded that Venezuela return assets that it seized from U.S. oil companies years ago, justifying anew his announcement of a “blockade” against oil tankers traveling to or from the South American country that face American sanctions.

Trump cited the lost U.S. investments in Venezuela when asked about his newest tactic in a pressure campaign against Maduro, suggesting the Republican administration’s moves are at least somewhat motivated by disputes over oil investments, along with accusations of drug trafficking. Some sanctioned tankers already are diverting away from Venezuela.

“We’re not going to be letting anybody going through who shouldn’t be going through,” Trump told reporters earlier this week. “You remember they took all of our energy rights. They took all of our oil not that long ago. And we want it back. They took it – they illegally took it.”

U.S. oil companies dominated Venezuela’s petroleum industry until the country’s leaders moved to nationalize the sector, first in the 1970s and again in the 21st century under Maduro and his predecessor, Hugo Chávez. Compensation offered by Venezuela was deemed insufficient, and in 2014 an international arbitration panel ordered the country’s socialist government to pay $1.6 billion to ExxonMobil.

The targeting of tankers comes as Trump has ordered the Defense Department to carry out a series of attacks on vessels in the Caribbean and eastern Pacific Ocean that his administration alleges are smuggling fentanyl and other illegal drugs into the United States and beyond.

At least 104 people have been killed in 28 known strikes since early September.

The strikes have faced scrutiny from U.S. lawmakers and human rights activists, who say the administration has offered scant evidence that its targets are indeed drug smugglers and that the fatal strikes amount to extrajudicial killings.

The Coast Guard, sometimes with help from the Navy, had typically interdicted boats suspected of smuggling drugs in the Caribbean Sea, searched for illicit cargo, and arrested the people aboard for prosecution.

The administration has justified the strikes as necessary, asserting it is in “armed conflict” with drug cartels aimed at halting the flow of narcotics into the United States. Maduro faces federal charges of narcoterrorism in the U.S.

The U.S. in recent months has sent a fleet of warships to the region, the largest buildup of forces in generations, and Trump has stated repeatedly that land attacks are coming soon.

Maduro has insisted the real purpose of the U.S. military operations is to force him from power.

White House chief of staff Susie Wiles said in an interview with Vanity Fair published this week that Trump “wants to keep on blowing boats up until Maduro cries uncle.”