The search for a 2-year-old boy, who was snatched by an alligator at a Disney hotel in Florida, has turned into a recovery effort, officials said on Wednesday.

"We're dealing with this family now where there's no question will lose a 2-year-old child," Orange County Sheriff Jerry Demings said.

He said that every effort is to try to bring closure to the family by recovering their loved one.

Disney closed all beaches in its resort area in response to the incident on Tuesday evening in a lagoon outside the upscale Grand Floridian Resort & Spa on Tuesday night.

By midday on Wednesday, the child had been declared missing for over 15 hours.

The search and rescue effort began after eyewitness reported seeing the boy being taken under the water by the alligator.

Demings told reporters that the search would not stop until the boy's body is found.

The boy had been relaxing with his family by the Seven Seas Lagoon when he was attacked by the alligator.

His father jumped into the water, but failed to wrestle his son from the animal, which was described between 1.2-metres and 2.1-metres long, the Orlando Sentinel reported.

The parents alerted a lifeguard before some 50 members of the Reedy Creek Fire Rescue, Orange County and the Florida Fish and Wildlife officials joined forces in the search.

An official from the Florida Fish and Wildlife Service said they were working with police officials to trap alligators in the area and manage other wildlife within the man-made lake to help find the body.