Jimmy Carter celebrates his 100th birthday on Tuesday, making him the first US president to reach the milestone.
Carter, a Democrat who served in the White House from 1977 to 1981, has spent the past 19 months in hospice care in his home state of Georgia.
But the former peanut farmer, who first entered politics in the 1960s as a state senator, is "emotionally engaged and still having experiences and laughing, loving", his grandson, Jason, said in September.
And the centenarian still has political ambitions: "I'm only trying to make it to vote for Kamala Harris" in November's election, the humanitarian and Nobel Prize recipient said, according to his grandson.
To honour the occasion, volunteers with Habitat for Humanity - the housing charity Carter has worked with for 40 years - are building 30 homes in Minnesota this week.
Several events were organised in Plains, the former Georgia governor's hometown, to celebrate the occasion on Tuesday.
The day began with a naturalisation ceremony for 100 people from 30 separate countries who all became US citizens. In the afternoon, a military flyover - including four F-18 jets - graced the skies over Plains.
It comes after a star-studded concert was held in Atlanta, Georgia, earlier this month to celebrate the 39th president's milestone birthday and to raise funds for The Carter Center.
"It was an incredible evening, full of good music and heartfelt tributes, and it made history as the first-ever 100th birthday celebration for a living American president," Carter said at the time.
The concert, which raised more than $1.2m (£900,000) and also featured recorded messages from other presidents, will air on Georgia Public Broadcasting on Tuesday. Dozens of musical acts performed at the event and thousands attended.
The former president will be watching the broadcast on Tuesday, his family said.
Carter, who was not able to attend the concert in person, made a rare public appearance in November 2023 when he attended a memorial service for his wife Rosalynn who died aged 96 earlier that month.
Their 77-year marriage remains the longest of any first couple.
When Carter first entered hospice care in Plains, Georgia, in February 2023, some relatives reportedly felt he only had a matter of days left to live.
“It’s a gift,” Josh Carter, another of his grandsons, said of the last few months in a recent interview with the New York Times. “It’s a gift that I didn’t know we were going to get.”
Others say Carter's story has also raised awareness of the benefits of hospice care. "We are all rooting for Jimmy Carter," Barbara Pearce, the CEO of Connecticut Hospice, told the BBC's US partner CBS News.
"He has done more for us than we could ever do for ourselves by pointing out that it's a reasonable choice to make," she said. "He's given everybody permission to consider [hospice care] as a reasonable option that doesn't shorten their life, but does increase their comfort and fulfilment."