Former President Jimmy Carter backed off Monday from harshly critical comments he made of President Bush over the weekend after the White House offered a biting rebuke to the former president by calling him "increasingly irrelevant."

"My remarks were maybe careless or misinterpreted but I wasn't comparing the overall administration and certainly not talking about anyone personally," Carter said in an interview Monday when asked to explain.

The comments "were interpreted as comparing this whole administration to all other administrations when what I was actually doing was responding to a question about foreign policy between [President Richard] Nixon and this administration, and I think that this administration's foreign policy compared to Nixon's was much worse. ... I wasn't comparing this administration with other administrations throughout history but just with President Nixon's," he told NBC's "The Today Show."

Carter, whose administration was plagued by sky-high inflation and a 444-day American hostage crisis in Iran, was filling in a quote Saturday in which he said, "I think as far as the adverse impact on the nation around the world, this administration has been the worst in history."

The Georgia Democrat said Bush had overseen an "overt reversal of America's basic values" as epressed by previous administrations, including that of his own farther, former President George H.W. Bush.

Carter made the comments to the Arkansas Democrat-Gazette in a story that appeared in the newspaper's Saturday editions. Sunday, the White House bit back.

"I think it's sad that President Carter's reckless personal criticism is out there," White House spokesman Tony Fratto responded from Crawford, 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."

But Bush would not respond directly to Carter.

"I get criticized a lot," Bush said Monday when asked about the former president's remarks during a press availability with NATO's secretary-general from Crawford. "I understand some people may not agree with the decisions I make but the American people need to know that I am making them based on what's best for this country."

Carter, who runs the Carter Center and whose latest book on the Mideast has been deemed anti-Semitic by some, said he doesn't "claim to have any relevancy" on the Iraq issue, though he has sent reports to the president and Secretary of State Condoleezza Rice on his personal activities monitoring elections around the world.

He said Monday he has "not been timid about sharing my opinions with those leaders but obviously I don't have any authority."

Carter added that if it were up to him, he would follow recommendations of the Baker-Hamilton commission to discuss the Iraq situation with Iran and Syria, something the Bush administration has done, and would set a deadline for withdrawal based on the ability of the Iraqi government to meet benchmarks for a political solution to the violence there.

Asked about the former president's comments, 2008 White House hopeful Sen. Hillary Clinton said she, too, has been very critical of the Bush administration but hasn't yet done so as a former president.

"I think it's the duty of every American to speak out when you feel strongly that your president is headed in the wrong direction. ... And I think we need to have a very vigorous debate. So I welcome everyone to that," she said appearing separately from Carter on the same program.

The Associated Press contributed to this report.