South Carolina Gov. Henry McMaster appointed Darline Graham Nordone on Monday to serve the remainder of her brother, late U.S. Sen. Lindsey Graham's, term following his sudden death on Saturday.
McMaster announced the appointment during a ceremony in Columbia, the state capital, saying Graham had always looked after his younger sister.
"Lindsey took care of his little sister," McMaster said. "It's my honor to ask his little sister, Darlene Graham, to finish his work for him now."
Nordone accepted the appointment and said her brother had always supported her. She pledged to complete the remainder of his term and continue supporting President Donald Trump.
Graham's office said the senator died following a brief and sudden illness.
Preliminary postmortem findings identified the cause of death as an aortic dissection resulting from arteriosclerotic cardiovascular disease.
According to Axios, Graham spoke with Trump on Saturday night about Ukraine, additional sanctions on Russia and renewed U.S. military action against Iran.
He reportedly complained of feeling unwell after the call but declined immediate medical attention.
Graham later joked, "I can't die now. I still need to do the Russia sanctions, get Iran sorted out and do Israeli-Saudi normalization."
He died several hours later.
Graham was first elected to the U.S. Senate in 2002 and was seeking a fifth term in the November election.
He became a close ally of Trump and served as chairman of the Senate Budget Committee.
Graham was also an outspoken supporter of Israel throughout the war in the Gaza Strip, which began in October 2023.
Since then, Israeli forces have killed 73,118 Palestinians and injured 173,615, while about 90% of civilian infrastructure in Gaza has been destroyed.
Graham also strongly supported Ukraine and had returned shortly before his death from a visit to Kyiv, where he met Ukrainian President Volodymyr Zelenskyy.
During his final reported conversation with Trump, Graham discussed Ukraine and further sanctions against Russia, alongside possible renewed U.S. military action against Iran and Israeli-Saudi normalization.