The U.S. military flew a pair of fighter jets over the Gulf of Venezuela on Tuesday in what appears to be the closest American warplanes have come to the South American country’s airspace since the start of the Trump administration’s pressure campaign.

Public flight-tracking websites showed a pair of U.S. Navy F/A-18 fighter jets flying over the gulf — a body of water bounded by Venezuela and only about 240 kilometres at its widest point — and spending more than 30 minutes over its waters.

A U.S. defence official confirmed a pair of jets conducted a “routine training flight” in the area.

The official, who spoke on condition of anonymity to discuss sensitive military operations, could not say if the jets were armed but noted they stayed in international airspace during their flight.

The official likened the training flight to previous exercises that were aimed at showing the reach of U.S. planes and said the move was not meant to be provocative.

Land attacks coming soon, Trump says

The military has previously sent B-52 Stratofortress and B-1 Lancer bombers to the region, but those planes flew along the coast of Venezuela. There was no indication those aircraft ever flew as close to the country’s territory as the F/A-18 fighter jets did on Tuesday.

In recent months the U.S. military has built up its largest 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.

U.S. President Donald Trump says land attacks are “coming soon” but has not offered any details.

Venezuelan President Nicolas Maduro has insisted the real purpose of the U.S. military operations is to force him from office.

Trump threatens strikes on any country trafficking drugs into the U.S.

Lawmakers demanding answers

Meanwhile, the Trump administration is facing increasing scrutiny from lawmakers over the boat strike campaign, which has killed at least 87 people in 22 known strikes since early September, including a strike Sept. 2 that killed two survivors clinging to the wreckage of a boat after an initial hit.

Lawmakers are demanding to see unedited video of the strikes, but U.S. Defence Secretary Pete Hegseth told congressional leaders Tuesday he was still weighing whether to release it.

Hegseth provided a classified briefing for congressional leaders alongside U.S. Secretary of State Marco Rubio and other top national security officials.

Earlier, Admiral Alvin Holsey, who will be retiring from U.S. Southern Command in this week, spoke separately with the Republican chair and ranking Democrat on the Senate Armed Services Committee.

Committee chair Sen. Roger Wicker declined to discuss the specifics of the call, but said the Pentagon is weighing whether releasing the video would disclose classified information.

U.S. lawmakers ramp up pressure to release boat strike video

Lawmakers are also questioning what intelligence the military is using to determine whether the boats’s cargo is headed for the U.S.

Lawmakers learned that the boat destroyed on Sept. 2 was heading south at the time of the attack and military intelligence showed it was headed toward another vessel that was bound for Suriname.

Still, it remains to be seen whether the Republican-controlled Congress will push back on the Trump administration’s campaign.

“I want a full set of data to draw my conclusions from,” said Sen. Thom Tillis, a North Carolina Republican who had previously demanded accountability after it was revealed that two survivors had been killed.

Trump has justified the attacks as a necessary escalation to stem the flow of drugs into the United States and asserted the U.S. is engaged in an “armed conflict” with drug cartels.

Flightradar24, one of the websites that allowed the public to see the jets flying in real time, said the planes were the most tracked flights on its site at the time.

Venezuela has claimed the body of water is part of the country’s territory, but those claims have been challenged by U.S. legal scholars and the military for decades.

Sept. 2 strike ‘illegal’: Republican senator

A group of senators — three Democrats and one Republican — is also preparing to force a vote on legislation as soon as next week that would halt Trump’s ability to use military force against Venezuela without congressional approval.

Sen. Tim Kaine, a Virginia Democrat who is sponsoring the legislation, said after reading the classified legal opinion from the Department of Justice that underpins the boat strikes, he had “deep skepticism about the legality of any of these operations.”

The senators have already tried to pass a similar resolution, but almost all Republicans voted against it. However, the senators say there is renewed interest from Republican lawmakers amid the Trump administration’s increasing threats against Venezuela, as well as scrutiny on the strike that killed survivors.

Sen. Rand Paul, the Kentucky Republican who is also sponsoring the legislation, called for a public hearing from Holsey. He argued the laws governing when it is legal to fire on shipwrecked troops also protect American soldiers who are caught in the same situation.

“These follow-on strikes of people who are wounded in the ocean is really against our code of military justice,” he said. “They are illegal.”