Domino’s Pizza stock fell 10% in morning trading on Monday after it reported weaker-than-expected U.S. same-store sales growth.

The chain’s domestic same-store sales rose just 0.9%, lower than the 2.3% bump expected by Wall Street analysts, based on StreetAccount estimates.

“We’re not happy with it,” CEO Russell Weiner told CNBC.

The pizza chain also lowered its full-year U.S. same-store sales forecast to low-single digit growth, down from its prior projection that U.S. same-store sales will increase 3%.

Weiner said he expects more fast-food chains to report similar headwinds from winter weather and weak consumer sentiment, which took a dive in March due to spiking fuel prices caused by the U.S.-Israeli war with Iran.

“One of the bad things about reporting first is you don’t get to hear about anybody else,” Weiner said.

Domino’s kicked off the earnings season for restaurant chains. Starbucks is on deck after the bell on Tuesday, and Chipotle Mexican Grill and Pizza Hut owner Yum Brands are expected to share their results on Wednesday. Rival Papa John’s will report its earnings next Thursday.

During the quarter, Domino’s also faced stiffer competition from rival pizza chains. Papa John’s and Pizza Hut both matched Domino’s $9.99 “Best Deal Ever” with promotions at the same price point. And Little Caesars undercut Domino’s $6.99 Mix & Match deal with a $5.99 version.

“People are seeing what we’re doing, and they’re sick of losing share, and they’re coming at it,” Weiner said, adding that he still expects Papa John’s and Pizza Hut to report same-store sales declines for the quarter despite the new promotions.

Looking ahead, Weiner expressed confidence that Domino’s will prove itself in the long run.

“Domino’s has got a bigger advertising budget than our second two competitors combined,” he said. “And those competitors are both going up for sale, so we know things aren’t good there right now.”

Yum announced in November that it was exploring strategic options for Pizza Hut, which could include a sale. And Papa John’s is reportedly in talks with Qatari-backed Irth Capital to go private. Both chains have also announced plans to close hundreds of restaurants this year, which could further boost Domino’s dominant position in the pizza category.

And if either Pizza Hut or Papa John’s goes private, Weiner said he expects that a new owner would shutter even more locations — a win for Domino’s.

Shares of Domino’s have lost nearly a third of their value over the last year. The company’s market cap has fallen to roughly $11.2 billion.

United Airlines CEO Scott Kirby confirmed Monday that he contacted American Airlines about a potential merger, a possibility American rejected.

“I approached American about exploring a combination because I thought we could do something incredible for customers together,” Kirby said in a statement. He said he shared his “big, bold vision” because he was confident it could win regulatory approval.

American rejected the idea and its CEO, Robert Isom, last week said such a merger would be bad for customers and “anticompetitive.”

Kirby had floated the idea to the Trump administration earlier this year, according to people familiar with the matter who weren’t authorized to discuss the private conversation, in hopes that the combination would mean a big global airline to compete with foreign rivals

American declined to comment on Kirby’s Monday statement.

“I was hoping to pitch that story to American, but they declined to engage and instead responded by publicly closing the door,” Kirby said in his statement Monday. “And without a willing partner, something this big simply can’t get done.”

He said that “American’s public comments make it clear that a merger like this is off the table for the foreseeable future” but outlined his vision for a combined airline.

Kirby reiterated that the country has deficit with foreign airlines that fly more than half of the long-haul seats into the U.S., with most of the customers being Americans.

“The combined scale of United and American would be a better way to compete with foreign carriers,” he said.

President Donald Trump said he was against the idea of a combination last week.

“I don’t like having them merge,” he told CNBC’s “Squawk Box” on Tuesday morning. He said he would, however, like someone to buy struggling discount carrier Spirit but he also suggested that the federal government could “help that one out.”

Spirit and the Trump administration are in advanced talks for a rescue package.