Joe Biden on Tuesday congratulated Jimmy Carter on his 100th birthday, a milestone that makes Carter the first former US president to reach a centenary.

Carter entered hospice care at his home in Plains, Georgia, 19 months ago. His grandson, Jason Carter, has said the former president would like to vote for Kamala Harris, a fellow Democrat, in the presidential election.

The White House paid tribute with large letters reading “Happy Birthday President Carter” and the number 100 outside the north portico. Carter has asked Biden to eulogize him at his state funeral when the time comes.

In a statement, 81-year-old Biden, the first sitting senator to support Carter’s 1976 election campaign, said his predecessor had always been “a moral force for our nation and the world.”

He added: “Your hopeful vision for our country, your commitment to a better world and your unwavering belief in the power of human kindness remain a guiding light for us all.”

Barack Obama posted a video message on the social media platform Thank you for your friendship, your basic decency, and your incredible acts of service through @CarterCenter. Michelle and I are grateful for everything you have done for this country.”

Carter, who has lived longer than any American president in history, served one term from January 1977 to January 1981 and was plagued by high inflation and the Iran hostage crisis. But recently historians have argued that his record deserves reappraisal, and he was ahead of his time in calling for action to tackle the climate crisis.

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

His birthday will be celebrated with the broadcast of a tribute concert by stars of country, rock and gospel music, taped at the Fox Theater in Atlanta last month. The concert raised more than $1 million for the Carter Center’s international program, which he founded with his wife Rosalynn Carter. The former president plans to tune into the concert on Georgia Public Broadcasting, according to his grandson Jason Carter.

Jimmy and Rosalynn Carter were married for 77 years. Rosalynn Carter died last November and the former president was last seen in public at his wife’s funeral, where he used a wheelchair and appeared weak. He was diagnosed with cancer and other health problems and decided to end medical intervention and enter hospice care in February 2023.

Carter is expected to celebrate his birthday in the same one-story home he and Rosalynn built in the early 1960s — before his first election to the Georgia Senate. Until a few years ago he taught Sunday school at his native Baptist church in Plains.

Jason Carter, chairman of the Carter Center’s board of directors, told the Associated Press: “Not everyone gets 100 years on this earth, and if someone does, and if he uses that time to do so much good for so many people , then it’s worth celebrating.

“These last few months, 19 months, now that he’s been in hospice, it’s been an opportunity for our family to reflect and then for the rest of the country and the world to really reflect on him. That was a really satisfying time.”

Early voting in Georgia begins Oct. 15, two weeks into Carter’s 101st year. Jason Carter added, “When we asked him about his 100th birthday, he said he was excited to vote for Kamala Harris.”

The Carters have worked with the nonprofit Habitat for Humanity International since the 1980s, and the ex-president has regularly joined other volunteers to help build homes for people affected by poverty or disaster.

This week, in celebration of Carter’s birthday, dozens of Habitat volunteers, including country music stars Garth Brooks and Trisha Yearwood, will build 30 homes in St Paul, Minnesota.

Jonathan Reckford, CEO of Habitat, said: “The Jimmy & Rosalynn Carter Work Project serves not only as a way to honor the Carters’ legacy, but also as a reminder of what is possible when people from all walks of life come together to to work towards one common goal.”