U.S. Senator Lindsey Graham, R-South Carolina, has died at the age of 71 following what his office described as a “brief and sudden” illness.

In a statement released early Sunday morning, Graham’s office confirmed the passing and said his family is requesting privacy during this difficult time. The longtime Republican senator had served in the Senate since 2003 after winning election in 2002. He had recently secured the Republican nomination for a fifth term.

President Donald Trump paid tribute to his longtime ally on Truth Social, calling Graham “a true American Patriot” who “will be greatly missed.” South Carolina Governor Henry McMaster described him as an “irreplaceable” leader and a loyal friend.

Graham served on several key Senate committees, including Appropriations, Judiciary, and Environment and Public Works. Before entering the Senate, he represented South Carolina’s 3rd District in the U.S. House of Representatives. A vocal voice on foreign policy throughout his career, Graham had just returned from meeting with Ukrainian President Volodymyr Zelenskyy in Kyiv on Friday and had been scheduled to appear on NBC’s “Meet the Press” this Sunday.

A veteran of the U.S. Air Force, Air National Guard, and Air Force Reserve, Graham retired as a colonel in 2015 after 33 years of service, including deployments during the Gulf War, Iraq, and Afghanistan.

Funeral arrangements have not yet been announced. His death marks the end of a more than three-decade career in Congress and leaves South Carolina with a major political vacancy just months before the November midterms.