Former US ambassador to the UN Bill Richardson has died aged 75, his foundation has announced.
Serving under President Bill Clinton, he won admiration for his commitment to securing the release of US citizens detained around the world.
He continued that work out of politics, last year travelling to Moscow to discuss the release of detained basketball star Britney Griner.
Mr Clinton hailed Mr Richardson as a “masterful” negotiator.
“Bill worked tirelessly for the causes of freedom, fairness, and opportunity,” Mr Clinton said in a statement on Saturday night.
“Whether in an official or unofficial capacity, he was a masterful and persistent negotiator who helped make our world more secure and won the release of many individuals held unjustly abroad.”
Born in Pasadena, California, in 1947 to a Spanish-born mother and a Nicaraguan-born father, Mr Richardson grew up in Mexico City before attending boarding school in Massachusetts.
After graduating from Tufts University in 1970, he earned a master’s degree in 1971. Soon after he embarked on a career in politics which would see him hold major national and state-wide offices.
In 1983 he was elected to the US House, representing New Mexico’s Third District.
Over the next five decades in politics he developed a specialisation in diplomatic negotiations, skills which would see President Clinton tap him as his envoy to the UN in 1997.
The next year he became Mr Clinton’s energy secretary, serving through to the end of the administration.
In 2002, he became the only Hispanic leader of a US state when he won the New Mexico governorship. His enduring popularity in the state saw him re-elected to a second term in 2006 by a record margin of 68% to 32%.
In his statement, Mr Clinton said his term as governor entrenched Mr Richardson’s status as a “trailblazer”, adding that his “career helped pave the path for other Latino Americans to serve at the highest levels of American government”.