Carter was quoted Saturday as saying "I think as far as the adverse impact on the nation around the world, this administration has been the worst in history."
The Democrat said Bush had overseen an "overt reversal of America's basic values" as expressed by previous administrations, including that of his own farther, former President George H.W. Bush.
"I think it's sad that President Carter's reckless personal criticism is out there," White House spokesman Tony Fratto said Sunday from Texas, where Bush spent the weekend.
"I think it's unfortunate," Fratto said. "And I think he is proving to be increasingly irrelevant with these kinds of comments."
Carter made the comments to the Arkansas Democrat-Gazette in a story that appeared in the newspaper's Saturday editions.
Carter spokeswoman Deanna Congileo confirmed his comments to The Associated Press on Saturday and declined to elaborate.
Brenton Tarrant, the shooter from New Zealand's Christchurch, was not a lone wolf. The West has missed out an important point - the formation of organised Christian extremism
Those who convientenly blame Muslims and Islam for "extremism" and "terrorism" should rethink and read the living history for truth, honesty and justice
The Moroccan occupation remains the last case of decolonization in Africa. The Moroccan military invaded in 1975 despite a clear ruling issued by the ICJ.