WASHINGTON (CBSDC/AP) — Former President Jimmy Carter claims he “could have wiped Iran off the map” when Americans were taken hostage after armed Iranians stormed the U.S. Embassy in Tehran in 1979.

“I could have wiped Iran off the map with the weapons that we had, but in the process, a lot of innocent people would have been killed. Probably including the hostages, and so I stood up against all that, all that advice, and then eventually my prayers were answered and every hostage came home safe and free,” Carter told CNBC.

Fifty-two Americans were held hostage for 444 days from November 1979 until January 1981. Carter believes he would’ve been re-elected if he took military action. Instead, he lost to Ronald Reagan.

“I could’ve been re-elected if I’d taken military action against Iran, shown that I was strong and resolute and manly and so forth,” Carter told CNBC.

Carter celebrated his 90th birthday Wednesday in Atlanta, blowing out three candles representing the past, present and future and thanking family and friends for their support and love.

“It’s been a good first 90 years,” the 39th president joked before telling the crowd gathered in a chapel on TheCarter Center grounds that he is looking forward to much more work. Carter and his wife, Rosalynn, founded the international health and human rights organization after leaving the White House.

Carter said his life was most shaped by his marriage to Rosalynn and growing up in Plains, Georgia, where he worked and played with black children who didn’t have the same rights as he because of their race. Carter said he still feels guilt for not realizing sooner how wrong that was.

Being elected president, he said, was the highlight of his political life. However, he said he’s had the “best times” of his life since establishing The Carter Center, “this beautiful place on earth that has set moral and ethical standards that exemplify what a superpower like America ought to be.”

Rosalynn Carter choked up while introducing her husband, telling him she’s proud of him for both his work and the family they built together. As for what’s next, Rosalynn Carter said only one thing is certain.

“It will be something because Jimmy Carter is miserable if he’s not doing something,” she said, laughing with the crowd.

Carter is the second-oldest of the five living U.S. presidents. He was born 111 days after President George H.W. Bush, who celebrated his 90th birthday earlier this year.

(TM and © Copyright 2014 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2014 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)