Lindsey Graham, the Republican foreign-policy hawk from South Carolina, died abruptly on Saturday following what his office described as "a brief and sudden illness," according to a statement posted on X.

"On the evening of Saturday, July 11, U.S. Senator Lindsey Graham passed away from a brief and sudden illness. Senator Graham's family appreciates prayers at this time and asks for privacy during this incredibly difficult period," Graham's office said.

Graham had served in the Senate since 2003 and was seeking a fifth term. He was in Kyiv on Friday before returning to Washington, where he was scheduled to appear on NBC's "Meet the Press" on Sunday morning.

Emergency personnel responded to his home in Washington on a reported cardiac arrest on Saturday evening, according to NBC News.

President Trump commented early Sunday on Truth Social about the passing of the senator, calling him a "true American Patriot."

Trump said, "Senator Lindsey Graham, one of the greatest people and Senators I have ever known, is dead! He was always working, and was a true American Patriot. Lindsey will be greatly missed!!!"

To note, Graham was on an Iranian kill list. Just days ago, Trump said if he was assassinated, then "bomb them at levels never seen before." 

Graham was once a fierce Trump critic, denouncing him during the 2016 presidential campaign before transforming into one of his most loyal supporters. He also advocated a hard line against Iran and consistently backed a strong US military posture overseas.