Former US President Jimmy Carter, pictured at a 2004 press conference, was a noted humanitarian in his post-presidency
Former US President Jimmy Carter, pictured at a 2004 press conference, was a noted humanitarian in his post-presidency AFP

Flags flew at half-staff across the United States on Monday as global tributes poured in for the life and legacy of Jimmy Carter -- the longest-lived US president who died aged 100.

The Georgia native, whose unlikely political ascent carried him from picking peanuts on the family farm to the Oval Office, was remembered in glowing eulogies as an ardent defender of human rights and champion of the downtrodden.

He will be honored with public observances in his beloved home state and in Washington in the coming days.

The first president to reach triple digits, Carter had been in hospice care in his home town of Plains since February 2023.

The Carter Center, his post-presidential humanitarian and pro-democracy organization, announced Sunday he had died "peacefully" at home "surrounded by his family."

The White House flag was lowered to half-staff, while President Joe Biden has scheduled a state funeral for January 9 and declared it a National Day of Mourning.

No formal announcements have been made about ceremonies in Georgia, although he is expected to be conveyed by motorcade to the state capitol in Atlanta, The New York Times reported, citing longstanding plans.

He will lie in repose for around 36 hours at the Carter Center, the organization said, before being flown to Washington to lie in state at the US Capitol for around the same duration.

He will be buried in Plains after the traditional televised funeral at Washington National Cathedral accorded to every US president.

Biden said in a heartfelt speech Sunday that Carter had "lived a life measured not by words, but by his deeds," while the country's living former presidents -- from Bill Clinton to Donald Trump -- lauded his public service, work ethic and commitment to justice.

The New York Stock Exchange -- which just suffered its longest losing streak since Carter was in the White House -- held a minute's silence.

International tributes were led by UN Secretary-General Antonio Guterres, Israeli President Isaac Herzog and China's President Xi Jinping, who said he was "deeply saddened," according to state media.

Pope Francis offered "heartfelt condolences," the Vatican said, recalling Carter's "firm commitment, motivated by deep Christian faith, to the cause of reconciliation and peace."

Carter voted for last time in November's presidential election, casting his ballot by mail, according to his family, after voicing determination to "live to vote for Kamala Harris," the Democratic vice president who was ultimately defeated by Trump.

He was the oldest ever former US president, outliving writers who contributed to his obituaries at The New York Times and Washington Post by seven years and 10 years respectively.

But his longevity had seemed unlikely when the Southern Democrat revealed in 2015 that he had brain cancer.

The US Navy veteran defied the odds to enjoy a long post-presidency, after four years in the Oval Office notable for his success in forging peace between Israel and Egypt, but overshadowed by the Iran hostage affair and his handling of an oil crisis.

The father-of-four lost in a landslide to Ronald Reagan in 1980.

Yet in the decades that followed, Carter's reputation grew through his humanitarian and diplomatic work and his efforts to build homes with his wife Rosalynn as part of Habitat for Humanity.

Carter won the Nobel Peace Prize in 2002 "for his decades of untiring effort to find peaceful solutions to international conflicts, to advance democracy and human rights, and to promote economic and social development."

The first US president born in a hospital, he taught Sunday school at Maranatha Baptist, his church in Plains, well into his 90s.

He was married for 77 years to Rosalynn, a fellow Plains native who had known Carter her entire life. By the time she died at age 96 on November 19, 2023, it was the longest presidential marriage in US history.

Carter's final public appearance was at his wife's memorial service, where he sat in the front row in a wheelchair.

Former US president Jimmy Carter receives hugs from the crowd after a press conference in Plains, GA
Former US president Jimmy Carter receives hugs from the crowd after a press conference in Plains, GA AFP
Former First Lady Rosalynn Carter died in November 2023 at age 96
Former First Lady Rosalynn Carter died in November 2023 at age 96 AFP
Carter brokered a peace deal between Egypt and Israel in 1978, dubbed the Camp David Accords, which leaders of both countries signed at the White House in March 1979
Carter brokered a peace deal between Egypt and Israel in 1978, dubbed the Camp David Accords, which leaders of both countries signed at the White House in March 1979 AFP