NEW YORK — A deadly storm ravaging the Texas and Louisiana coasts has led to a rare release of oil from emergency US stockpiles that President Trump wants to slash.

Just three months ago, Trump proposed selling half the Strategic Petroleum Reserve, which can hold more than 700 million barrels of crude, saying the stockpile was no longer useful in an era of surpluses. On Thursday, as gasoline prices surged, the Energy Department agreed to deliver 1 million barrels from the reserve to a refinery in Louisiana that was unable to get crude after Hurricane Harvey disrupted supplies, and followed up with an additional 3.5 million barrels. It was the first delivery in five years.

“What you saw today was an insurance payout,’’ said Kevin Book, managing director of ClearView Energy Partners in Washington, of the delivery. “The cost of maintaining that insurance is far, far lower than the value of that insurance in a true moment of scarcity.’’

Still, the cost of the strategic reserve is rising, and the storm illustrated the vulnerability of salt caverns along the Gulf of Mexico that the government first developed in 1977. The reserve’s proximity to Gulf Coast refining centers means it can respond to supply disruptions quickly. But they are susceptible to the same risks of hurricanes and storm surges that disrupt supply in the first place.