President Biden on Wednesday honored the late John Sweeney, former leader of the AFL-CIO labor union, calling him “a giant of the American labor movement, and a good man.”

Sweeney died Monday at the age of 86. His cause of death has not been disclosed. 

AFL-CIO spokeswoman Carolyn Bobb confirmed Sweeney's death, according to The Washington Post. 

“I had the honor and privilege of working closely with John Sweeney during his leadership of the AFL-CIO. Time and again over the many years of our friendship, I saw how lifting up the rights, voices, and dignity of working Americans was more than a job to him. It was a sacred mission. It was a calling,” Biden said in a press release on Wednesday afternoon.

“The work he led, from the factory floors of the garment workers early in his career to the highest corridors of power as a national labor leader, embodied the vital role that unions play in delivering greater wages and benefits for working people — union and nonunion alike,” Biden added.

Sweeney changed the AFL-CIO into a politically powerful organization, according to the Post, sending organizers across the country to help elect lawmakers who would advocate for laborers. Sweeney also aided in former President Obama’s 2008 presidential campaign. 

Sweeney was a longtime advocate for a national health insurance system, the Post added, and he advocated for the Affordable Care Act during the Obama administration. The former union leader was presented with the Presidential Medal of Freedom by Obama in 2011.

"Jill and I count ourselves among the millions of Americans who will always be grateful for the progress John won, the example he set, and the legacy he has left to our nation," Biden continued in his statement. "Our prayers are with John’s wife, Maureen, with their children, Trish and John Jr., and with his granddaughter, Kennedy."

Biden in the past branded himself as an advocate for labor unions, pledging often that he would be the "most pro-union president."

Prior to the 2020 November election, Biden won the endorsements of several major unions including North America's Building Trades Union, a coalition of 14 unions representing millions of workers across the U.S., according to Reuters.