The Iran war set off the “most severe oil supply shock in history,” the International Energy Agency (IEA) said in a new report on Tuesday, warning that high prices would slash demand for crude, the primary lifeblood of the global economy.

In March, oil prices notched their largest one-month gain ever, the IEA said.

The IEA – a Paris-based group made up of 32 member nations, including the U.S. – warned of a widespread bout of “demand destruction" in the report. Under such a scenario, high prices would make oil unaffordable for many buyers, forcing them to find alternatives or forgo energy use altogether.