“Senator Graham’s family appreciates prayers at this time and asks for privacy during this incredibly difficult period,” the statement added.

Graham, who had just turned 71 on Thursday, was a close ally of President Donald Trump and chairman of the Senate Budget Committee. In June, he defeated five Republican challengers in the Senate primary in South Carolina and was to face Democrat Annie Andrews in the general election.

Trump, on social media, called Graham “one of the greatest people and Senators I have ever known.”

“He was always working, and was a true American Patriot. Lindsey will be greatly missed!!! DETAILS AND ARRANGEMENTS TO FOLLOW. So sad!”

Graham, who had just returned from a visit to Ukraine, had been scheduled to appear on NBC's "Meet the Press" on Sunday morning. Instead, Trump appeared as a guest and told host Kristen Welker he spoke with Graham on Saturday night, “sometime in the sevens,” apparently not long before Graham died.

“He was really a worker but he sounded great, actually,” Trump said, adding that Graham said he was “a little tired” after the trip overseas.

“I got a message about 1 o'clock in the morning from one of the people in his office that he had passed away,” Trump said.

“He was a great politician actually,” said Trump, who had endorsed Graham. “There was nobody like him. He loved being a politician, and he was going to win his election, he was going to win it big.”

Trump said if he “had a problem with a Democrat, he could work it out,” and added that Graham in their final conversation underlined his advocacy for the SAVE America Act, an elections bill stalled in the Senate.

Asked by Welker if he had anyone in mind who should be appointed to the seat, Trump said, “I have somebody that I think would be great, but I don't want to say it now because … it's too soon.”

Republican Sen. Tim Scott of South Carolina, also on "Meet the Press," said, “The entire state has lost a statesman. I have lost a friend.” He said he expected at least one or two U.S. House members from South Carolina would be considered for the appointment to Graham's seat.

Former President Joe Biden, a Democratic member of the Senate from Delaware before his election to the presidency, said on social media he and Graham served together for more than a decade and worked closely on many issues as members of the Foreign Relations Committee.

“We disagreed often, and sometimes loudly,” Biden said. “Lindsey and I did agree on the profound importance of public service. Like me, he loved the Senate as an institution, even with all its flaws and complexities.”

Return from Ukraine

Graham, the chairman of the Senate Appropriations Subcommittee on State, Foreign Operations and Related Programs, met with President Volodymyr Zelenskyy while in Ukraine. Zelenskyy posted photos of the two on X on Friday.

“This is already his 10th visit to our country, and we appreciate this support,” Zelenskyy said.

Early Sunday, Zelenskyy posted on social media: “Deeply saddened by the news of the passing of United States Senator Lindsey Graham. Lindsey was a true defender of freedom and the values that make our world safer.”

He said they had met twice during Graham's most recent visit.

Graham's office did not provide additional details on the circumstances of his death.

The Washington Post, citing police scanner audio, reported that emergency responders at Graham's Washington, D.C., home worked to stabilize a man Saturday night and transported him to a hospital.

NBC News reported the response, according to emergency responders' audio, was to a call for “cardiac arrest” and CPR was in progress.

“Photographs from the scene reviewed by NBC News show paramedics carrying a person on a stretcher from Graham's home to an awaiting ambulance. Police cars and fire trucks were also on site,” NBC reported.

'My heart is heavy'

Senate Majority Leader John Thune, R-S.D., said in a statement “my heart is heavy” to learn of Graham's death.

“Lindsey's long and dedicated service in the Air Force and in Congress carried him to far-flung regions of the world,” Thune said. “He was a strong advocate for the United States and a strong ally to freedom-loving countries across the globe. He believed in the might of America to achieve good in the world and dedicated his life to advancing that cause.”

Graham, who was born in Central, South Carolina, first joined Congress in 1994 when he was elected to the U.S. House from the state's 3rd Congressional District. He was elected to the Senate in 2002 and reelected in 2008, 2014 and 2020.

He earned undergraduate and law degrees from the University of South Carolina and spent six and a half years on active duty as an Air Force lawyer. He then served in the South Carolina Air National Guard and Air Force Reserve, according to his official biography, retiring as a colonel in 2015.

Under the 17th Amendment to the U.S. Constitution, the governor must schedule an election to fill an empty Senate seat. South Carolina law allows the governor to appoint someone to fill the seat for the remainder of Graham's term, which expires in January.

South Carolina law also requires a special primary election to select the next Republican nominee for the seat Graham held. The special primary is set for Aug. 11, with a runoff, if needed, on Aug. 25.

Andrews, the Democratic Senate nominee, expressed her condolences on X.

“From his small-town South Carolina roots to the halls of the U.S. Senate, he was a man of great faith who proudly served our nation as a JAG officer and Air Force colonel,” she said. “I hope that South Carolinians will join me in setting partisanship aside and offering gratitude to Senator Lindsey Graham for his service to the great state of South Carolina.”

South Carolina Gov. Henry McMaster said on social media he and his family were “devastated” by Graham's death.

“Lindsey Graham is irreplaceable,” he said. “The fiercest of fighters for South Carolina and America – and a loyal and steadfast friend.”

Narrow margin in Senate

Republicans control the Senate with 53 seats.

Graham's death came as concerns have mounted about the continuing absence of 84-year-old Sen. Mitch McConnell, a Kentucky Republican, whose office has said he has been hospitalized since June 14 for an undisclosed condition.

Senators expressed their condolences after awakening Sunday to the unexpected news.

“I'm shocked and saddened by the passing of my friend and colleague Senator Lindsey Graham,” said Sen. Thom Tillis, R-N.C. “Lindsey was a lifelong public servant, a tireless champion for South Carolina, and an outspoken advocate for America's role in protecting freedom throughout the world.”

Senate Majority Whip John Barrasso, R-Wyo., said Graham represented South Carolina and America “with pride and determination. He guided the Senate through our toughest battles while chairman of both the Judiciary Committee and the Budget Committee. He carried the day with his mission clarity and steadfast leadership.”

Vice President JD Vance, a former Republican senator from Ohio, said on social media that Graham “came from humble beginnings and became one of the most powerful lawmakers in the most powerful nation on Earth.” Vance also recalled a shouting match they had during a Senate lunch over a Ukraine funding bill, saying he later learned Graham was quietly pushing rail legislation that Vance wanted.

“That was Lindsey Graham. He fought like hell for the things he believed in, and he was just as willing to go to bat for you when it counted,” Vance said. “Lindsey had the best sense of humor in the Senate. He loved the game of politics. He was constantly asking which races were up and down, and how he could help. As he liked to say, 'I don't care if you're an isolationist or a religious fanatic, so long as you have an R next to your name, I want you to win.'”