Ryanair has told Boeing that if any U.S. customers refuse to take delivery of 737 MAX 10 aircraft, that it would buy them "at the right price," executives said on Monday.

The Irish airline, Europe's largest by passenger numbers, already has 150 firm orders for the MAX 10, the largest jet in the 737 family, and options for 150 more, with the first deliveries due in 2027.

It said it expects the jet to be certified by the end of the year and flying early next year despite the Federal Aviation Administration's now-lifted grounding of MAX 9 jets following the mid-air blowout of a cabin panel on a new Alaska Airlines plane.

United Airlines CEO Scott Kirby, whose carrier has ordered 277 MAX 10 jets with options for another 200, said last week his airline would build a new fleet plan that does not include the model, which had already been mired in regulatory and delivery delays before the Alaska Airlines incident.

"We have told them if some of these American airlines don't want to take the MAX 10 aircraft, Ryanair will take those aircraft," Ryanair Group Chief Executive Michael O'Leary said in a presentation on the airline's quarterly results.

He described the MAX 10 as "transformational" and said Boeing would always make great aircraft "but quality does need to be improved."

Ryanair Chief Financial Officer Neil Sorahan said the comments last week by United's Kirby were "unhelpful."

"If Scott Kirby doesn't want to take his MAX 10s, then we'll very happily take them at the right price," Sorahan said in an interview.

Sorahan said he was "hopeful" the MAX 10 would be certified before the end of the year and flying at the start of 2025.

Ryanair currently has 136 MAX 8 aircraft and 409 earlier generation 737s in a fleet of 574 jets but plans to increase that eventually to 210 MAX 8s and up to 300 MAX 10s.

Asked if Ryanair was nervous about its huge reliance on the MAX or was looking at ways to diversify, Sorahan said: "No, I think the MAX is a great aircraft." But he said "if something were to happen", Ryanair would have the option of not selling its older 737s.

"But the reality is we're very keen to get our hands on as many of the 8200s and the 10s as we an to grow over the next few years," he said. The 8200 is the high-density version of the MAX 8 ordered by Ryanair.