Apple has decided to move away from the current, cylinder-shaped design used on its Mac Pro desktop, but creating a replacement will take until next year, executives said on Monday.

In a rare admission of a misstep, executives conceded the unusual design limited Apple's ability to offer meaningful upgrades and failed to meet many pro users' needs. Top executives said the company has begun work on a new desktop and a professional monitor.

"You won't see any of these products this year," Senior Vice President Phil Schiller told a handful of reporters in a discussion at Apple's offices in Cupertino. "It's important to do something great. That will take longer than this year to do."

(Related: Why the Mac Pro proved so hard to upgrade.)

In the interim, Apple plans to introduce new versions of the iMac with components more geared to professionals later this year. Also, later on Tuesday, it will announce a modest performance update to the existing Mac Pro in an attempt to tide over those who rely on Apple's highest-end machine. The updated configurations will add more processor cores and improved graphics performance.

Among the other points discussed: