Nobel laureate Jimmy Carter, who has lived longer than any US president in history, is celebrating his 100th birthday.

Carter, a Democrat, served a single term as president from January 1977 to January 1981. 

His decades of humanitarian work after leaving office, including the promotion of human rights and alleviating poverty in countries around the world, earned him the Nobel peace prize in 2002.

His birthday on Tuesday came 19 months after he entered hospice care in his home town of Plains, Georgia.

In a birthday tribute, US President Joe Biden, a Democrat, said Carter had always been “a moral force for our nation and the world”.

“Your hopeful vision of our country, your commitment to a better world, and your unwavering belief in the power of human goodness continues to be a guiding light for all of us,” the statement said.

The milestone birthday was marked by the broadcast of a tribute concert by stars of country, rock and gospel music recorded at Atlanta’s Fox Theatre in September. 

The concert raised more than $US1 million ($1.4 million) toward the international programs of the Carter Centre, which he founded with his wife, Rosalynn Carter. 

The former president planned to tune in to the concert on Georgia Public Broadcasting, according to his grandson Jason Carter.

Footage from America’s CBS News showed him being brought out in a wheelchair by hospice staff to join his family on a lawn to watch a flyover of aircraft in honour of his milestone birthday.

Jimmy and Rosalynn Carter were married for 77 years. 

Rosalynn Carter died in November 2023 and, until Tuesday, the former president was last seen in public at his wife’s funeral, where he used a wheelchair and appeared frail.

Jimmy Carter has been diagnosed with cancer and other health issues, and decided to end medical intervention and enter hospice care in February 2023.

The Carters have worked with the non-profit group Habitat for Humanity International since the 1980s and the former president has regularly joined other volunteers to help build homes for people affected by poverty or disasters.

This week, to mark Carter’s birthday, scores of Habitat volunteers, including country music stars Garth Brooks and Trisha Yearwood, will build 30 homes at St Paul, Minnesota, the group said.

“The Jimmy and Rosalynn Carter Work Project serves not only as a way to honour the Carters’ legacy but also as a reminder of what is possible when people from all walks come together to work toward one common goal,” said Jonathan Reckford, Habitat’s chief executive officer.

-AAP