BOSTON — United Airlines CEO Scott Kirby said the spike in fuel prices since the U.S. and Israel attacked Iran on Saturday will have a “meaningful” impact on the carrier’s financial results this quarter, but he added that demand has been resilient.

Jet fuel, airlines’ biggest expense after labor, has surged 58% since last Friday, going for $3.95 a gallon on Thursday, according to the Argus U.S. Jet Fuel Index.

“If it continues we’ll feel it in Q2 also,” Kirby said after an event Thursday afternoon where he discussed the future of air travel at Harvard John A. Paulson School of Engineering and Applied Sciences.

United, like most major U.S. carriers, doesn’t hedge fuel, a practice where airlines or other companies lock in prices using futures contracts or other products. A Boeing 737-800 can hold 6,875 gallons of fuel, according to a manufacturer guide.

“No one hedges anymore and even if you do, hedging the crack spread is really hard to do,” Kirby said. The crack spread is the difference between the price of crude oil and products like gasoline.

When asked when the higher fuel costs will start affecting airfares, Kirby said it will “probably start quick.” 

He added that travel demand has been resilient over all, with booked revenue up 20% from a year ago. Demand “has not taken even a tiny step back,” he said.

Kirby spoke less than two weeks before airlines are set to attend a closely watched JPMorgan industry conference where airline executives often update their financial outlooks.

His comments are an early sign of how global airlines are impacted by the war, which left more than a million people stranded after over 25,000 flights were canceled, forcing customers to find alternatives to flight chaos in the Middle East.

A new segment is emerging for United because so many customers have been caught up in airspace closures and massive flight cancellations in the Middle East since Saturday’s attacks and other strikes throughout the week.

Dubai International Airport in the United Arab Emirates is the busiest international airport in the world, according to the Airports Council International, while Hamad International Airport that serves Doha, Qatar, is another major hub.

The airports are gateways to millions of passengers flying to and from destinations that span Australia, India, Europe and North America. But customers have been forced to avoid the Middle East amid airspace closures.

“Each day this week, we have booked over 1,000 people from Australia and New Zealand to Europe. Last year, we booked less than one a day,” Kirby said, adding that Europe is the strongest region in the world for bookings now.

United is also in talks with the Trump administration for potential charter flights to get citizens out of the Middle East, Kirby said, but that plans haven’t been set yet.