Aug. 19 (UPI) — President Donald Trump declared “economic warfare” against Iran on Wednesday night amid stalled diplomatic efforts to end the war.

Few specifics were offered about what this apparent intensification of Trump’s maximum pressure campaign would look like, but the president said it would be “the MOST CRUSHING ECONOMIC OPERATION EVER TAKEN AGAINST ANY COUNTRY!”

“This will be Economic Warfare and Isolation on an unprecedented scale,” Trump said in his social media statement.

Financial institutions, businesses, airports and government entities accused of providing “any type of lifeline to Iran” will face what Trump called “TREMENDOUS Economic Consequences,” though he did not elaborate further.

“Oil smuggling, swap lines, cash transfers, exchange houses, ship registries, front companies — It all needs to stop NOW,” he said. “You know who you are. This will be an ECONOMIC D-DAY.”

To enforce the plan, Trump called on all U.S. allies to work with Washington to isolate Iran.

“These maniacs are on the ropes, and these HISTORIC MEASURES will cripple them and their ability to project terror worldwide,” he said.

The announcement came hours after Trump told reporters at the White House that there are more sanctions the United States could impose on Iran.

“Well, we have things that we could sanction,” he said. “We have very draconian sanctions and we’ll see what happens.”

Earlier Wednesday, Trump also said formal negotiations with Iran could restart “at some point,” while suggesting there was no urgency to resume talks.

“Right now, I think the situation is so good, but maybe at some point,” he said.

Trump has long relied on economic pressure as a means to coerce Iran. During his first term, after unilaterally withdrawing the United States from an Obama-era multinational accord aimed at preventing Iran from obtaining a nuclear weapon, Trump launched his maximum pressure campaign of sanctions and other punitive measures against Tehran, failing in its objective to force Iran back to the negotiating table on a new deal. Instead, Iran began gradually reducing its compliance with the nuclear accord.

Trump reinstated that maximum pressure campaign after returning to the White House last year. The Treasury has since folded its sanctions efforts into a campaign it calls Economic Fury, complementing Operation Epic Fury, the U.S. military campaign that began Feb. 28 and ended May 5, though the broader war continues.

Trump has been seeking a phased end to the war, but negotiations have stalled over competing demands concerning the Strait of Hormuz. The United States is seeking to restore freedom of navigation through the important energy route, while Iran is seeking to retain the leverage it gained by restricting passage through the strait.