President Trump’s cease-fire with Iran in June envisioned a broader deal to end the war and rein in the country’s nuclear program, all negotiated within 60 days.

But that deadline, set to pass on Monday, has been essentially abandoned, and the war has transformed into a contest of willpower and economic endurance that has no end in sight.

There have been no publicly reported U.S. strikes on Iranian targets since late July. Yet the effective collapse of the agreement underscores how Mr. Trump has struggled to end the war he started in February alongside Israel, and how far he remains from the ambitions of the June deal, including fully reopening the Strait of Hormuz, a critical waterway where Iran has choked off oil and gas shipping since the fighting began.

Those inside the White House are well aware that they will blow past Monday’s deadline and that the conflict has largely morphed into one of economic warfare, according to two Americans familiar with the negotiations.

The current strategy bears a striking resemblance to previous, yearslong U.S. attempts to isolate Iran in the hopes of compelling it to abandon its nuclear ambitions. The policy had mixed results, and some analysts are skeptical that even severe economic pressure on its own will force Iran to change course. After all, that was the approach Mr. Trump attempted in his first term, even though his Treasury secretary, Scott Bessent, said last week that he was about to impose financial penalties unlike any seen before.

The June memorandum of understanding was widely seen as a boon for Iran, granting the regime badly needed sanctions relief even as talks over tough concessions like nuclear enrichment were postponed for later. But Iranian leaders opted to escalate again rather than consolidate their gains from the deal, according to Nate Swanson, an Iran expert at the Atlantic Council, a Washington-based research group.