$Delta Air Lines(DAL.US)$ said that surging travel demand is helping offset a sharp rise in the price of jet fuel, as the airline anticipates a bustling summer.

Delta on Wednesday reported a $940 million loss over the three months ended March 31, but said it returned to profitability during March, despite soaring fuel prices, and expects to report a profit in the second quarter.

The Covid-19 Omicron variant's surge was a setback to airlines at the start of the year. Leisure travelers called off trips, businesses held back on bringing workers back to offices and airline operations were thrown into disarray as workers called in sick.

But that quickly shifted as case numbers began to fall.

"We are seeing an historic level of sales activity and booking volumes at levels higher than we've ever seen in our history," Delta Chief Executive Ed Bastian said. Even concerns about the spread of the Omicron BA.2 variant, which recently has driven increases in case numbers in some parts of the country, haven't derailed demand, Mr. Bastian said in an interview.

"There appears to be no concerns, candidly, about any variant or the virus," he said. "Everyone is ready to get past it."

Rising jet-fuel prices are now one of the biggest threats to airline profits, but executives have said they are confident they can shake them off.

Prices climbed to their highest levels since 2008 as Russia's invasion of Ukraine drove a surge in crude-oil prices last month. Delta reported a 33% increase in jet-fuel prices during the first quarter, to $2.79 a gallon. The company said it expects the price to climb to as high as $3.35 a gallon, including a 20 cent-a-gallon benefit from its refinery, in the second quarter.

Airfares have started to climb to match as carriers pass those higher costs on. Domestic ticket prices in March were 20% higher than 2019 levels, and up 15% from February, according to the Adobe Digital Economy Index.

Delta said it has been successful in recouping the higher fuel prices, and expects its revenue in the second quarter to reach 93% to 97% of 2019 levels. Typically it takes a few months for ticket prices to catch up with rising costs, but Mr. Bastian said demand is so strong that there hasn't been much of a lag.

"Given the strength of the demand environment, we've largely been able to recapture -- real time -- the price increases that we have experienced," he said. "That is a bit unprecedented."

"The pricing environment is entirely driven based on demand," he said.

Delta reported an adjusted net loss of $784 million, or $1.23 a share, beating the $1.27 analysts expected, according to FactSet. Delta reported operating revenue of $9.3 billion during the first quarter, including nearly $1.2 billion in third-party sales from the oil refinery it owns.

Corporate and international travel, mainstays of Delta's business, also started to bounce back during the quarter, the company said. Lucrative business travelers have been slower to return than vacationers, who have more or less gotten back to prepandemic levels of flying.

Delta said domestic corporate sales were 50% of 2019's level during the quarter, and hit 70% in March. International sales showed similar gains, climbing to 50% of 2019 levels in March.

Delta plans to operate at 84% of its 2019 capacity levels in the second quarter, a level of flying that Mr. Bastian described as "disciplined," as the airline tries to avoid the growing pains and staffing shortfalls that have led some rivals to cut schedules in recent weeks. Delta is hiring about 200 pilots a month as it looks to ramp up.

"We've been balanced, we've been disciplined, we've been ahead of it," Mr. Bastian said.