U.S. President Donald Trump and Vice President JD Vance say their interim deal to end the war with Iran will deliver a financial windfall to American farmers.

But the Iranians deny it. And, in the absence of more details, sanctions experts are flummoxed over exactly how billions of dollars’ worth of Iranian assets would make their way to the American heartland from the escrow accounts where they’ve been locked for years by U.S. sanctions.

A tentative agreement reached last week would reopen the Strait of Hormuz, through which a fifth of the world’s oil and natural gas once passed, and allow Iran to start selling its oil freely again during a 60-day period when the two countries will continue negotiating key issues. The memorandum of understanding also promised to unfreeze Iranian assets.

Trump’s deal has come under fire for failing to address the reasons the president cited for going to war with Iran on Feb. 28, including curbing Tehran’s nuclear ambitions, its missile program and its support for militant groups such as Hezbollah in Lebanon and Hamas in Gaza.

Lashing back at critics Tuesday on his Truth Social media platform, Trump said U.S. farmers would get a payday: The U.S. Treasury Department, he wrote, would release the Iranian assets “into escrow, controlled by the U.S.A., and will be used for the purchase of food and medical supplies, exclusively from the United States, including Corn, Wheat, and Soybeans from our great American farmers. These are things that are desperately needed by Iran.’’

Vance, who spoke about the proposal after high-level talks in Switzerland, and Trump say that any frozen funds and assets held outside of Iran will be used to buy U.S. crops.