President Donald Trump isn't sending warm and fuzzy vibes this Easter weekend ... he's dropping F-bombs and threatening Iran with "Hell."

Fresh off a dramatic U.S. military rescue of a downed airman inside Iran, Trump fired off a Truth Social post Sunday, issuing a blunt warning over the Strait of Hormuz crisis.

"Open the F***ing Strait, you crazy bastards, or you'll be living in Hell -- JUST WATCH!" he wrote.

Earlier, Trump praised the high-risk overnight mission that pulled a wounded F-15 crew member out of Iran's mountains, saying Iranian forces were closing in fast and calling the rescue rare and dangerous.

He also doubled down on his deadline for Iran to reopen the Strait of Hormuz ... a key global oil route disrupted since the conflict escalated in February.

"48 hours before all Hell will reign down on them," he warned Saturday. "Time is running out."

Trump then hinted at possible strikes, writing, "Tuesday will be Power Plant Day, and Bridge Day" -- appearing to signal potential hits on major infrastructure.

The U.S. recently struck a major bridge in Iran, which officials say supported missile and drone operations.