Officials did not specify when the giraffe is expected to give birth.
"As we await the newborn, the source of excitement is whether baby will be white, too," KWS tweeted.
Although the agency said the white giraffe is the only one of its kind, one commenter pointed out that the statement may not be completely accurate.
"Your post should have read 'possibly only entirely white giraffe' in the world," tweeted Odeo Sirari, a news editor for the Kenya Television Network.
A white mother giraffe and very pale calf – likely the ones mentioned in the agency's initial tweet – also were spotted at Hirola in 2017, National Geographic reported. Another pale giraffe was seen at Tanzania's Tarangire National Park in 2016.
Wildlife researchers believe that the giraffes have leucism, a genetic contition that "inhibits skin cells from producing pigment but allows other organs, like eyes, to be dark colored," National Geographic reported.