Former New Mexico Governor Bill Richardson has died aged 75, according to a statement from his representatives.
Mr Richardson was Energy Secretary and United Nations ambassador during former President Bill Clinton's administration. He died on Friday, according to the Richardson Centre for Global Engagement.
Mr Richardson reportedly died in his sleep at his summer home in Massachusetts, according to CNN.
Mickey Bergman, the vice president of the Richardson centre, remembered its namesake as a man who dedicated his entire life to public service.
“He lived his entire life in the service of others – including both his time in government and his subsequent career helping to free people held hostage or wrongfully detained abroad. There was no person that Governor Richardson would not speak with if it held the promise of returning a person to freedom,” Mr Bergman said.
He said the world lost a "champion," and that he "lost a mentor and a dear friend."
Mr Richardson was first elected to the US House in 1983, and then later served as an ambassador and in Mr Clinton’s cabinet.
In 2002 he launched a sucessful bid for the New Mexico governor’s seat. He served two terms and left office in 2011.
Mr Richardson set his political ambitions high; he ran for the presidency in 2008, but lost. He later launched the Richardson Centre for Global Engagement, an international peace nonprofit founded in 2011.
Neda Sharghi, the chair of Bring Our Families Home Campaign, which works to return Americans imprisoned overseas to the country, remembered the former governor’s work to reunite families.
“On behalf of the countless families that Governor Richardson and his Center have helped, I wanted to express our profound feeling of loss at his passing,” the chair said.
Senator Martin Heinrich of New Mexico said Mr Richardson’s “legacy will have a lasting impact,” in a statement, posted to X/Twitter.
“Gov. Richardson believed New Mexico could do big things. His ambition for our state meant he never accepted mediocrity and always pushed us to fight for the future we deserved. I was privileged to serve in his administration and will forever be grateful for all that he taught me,” Mr Heinrich said.
Friends and colleagues remembered the former governor Monday on social media.
I’m sad to hear of former NM Gov Bill Richardson’s passing,” Secretary of the Interior Deb Haaland wrote. “He was a champion for Tribes, elevating Indian Affairs to a cabinet level. He helped me ensure Native students received in-state tuition. He was true friend and one of our country’s valued diplomats.”
US Congressman Gabe Vasquez of New Mexico said Mr Richardson was a “titan” and said he mourned the passing of “one of the most powerful Hispanics in politics that this nation has seen.”
Former Vice President Al Gore, who served alongside Mr Richardson under Mr Clinton, issued his own remembrance in an X/Twitter statement.
“I am saddened to hear the news of Bill Richardson’s passing,” Mr Gore said. “He was an exceptional public servant, a relentless advocate for those unjustly held overseas and a true friend. I send my deepest condolences to the Richardson family during this difficult time.”