CHICAGO — When President-elect Barack Obama warned it would take time to fulfill his many campaign promises, few imagined that his daughters' puppy would be among those immediately placed on the back burner.

"This is a major issue," Obama told reporters at his news conference Friday. It's generated more interest on his Web site than any other topic, he joked.

Despite widespread interest in the future first pup, the Obamas will wait until spring to adopt a pet, according to his transition staff.

Aides were quick to point out that Obama was not reneging on a promise. When he and his wife first agreed to let Malia and Sasha have a dog, it was always on the condition that the adoption take place in the spring so they wouldn't be housebreaking the puppy in the winter.

The Obamas favor adopting a dog from a rescue shelter. The hitch is that any Obama pet must have a hypoallergenic coat because of Malia's allergies.

"But obviously, a lot of shelter dogs are mutts like me," said Obama, in an apparent reference to his mixed-race heritage. "So whether we're going to be able to balance those two things, I think, is a pressing issue on the Obama household."

Malia, 10, reportedly wants a goldendoodle, a golden retriever-poodle hybrid that isn't recognized as an official breed by the American Kennel Club.

Obama's transition office has been deluged with e-mails and phone calls from people offering their input on choosing a dog.

The Associated Press contributed to this report.