The United States has a new senator after the sudden and unexpected death of Lindsey Graham, a Republican senator for South Carolina.

Graham's term will be finished out by his sister, Darline Graham Nordone, who was appointed by Republican South Carolina Gov. Henry McMaster.

'To Lindsey, I miss you more than I can even put into words. But I'm going to do this. I got it.'

Nordone accepted the appointment in a news conference Monday with McMaster in Columbia, South Carolina.

"I want to thank the governor for selecting me to serve the remainder of Lindsey’s term," she said. "It is such an honor. Lindsey has always been there for me, and now I will be there for him."

Graham's death was announced early Sunday morning.

"It is such a privilege to get to finish some of his important work, and I promise to work hard over the next several months to support the president and carry forward the efforts of my brother on behalf of the citizens of South Carolina and the United States," Nordone continued.

"I know Lindsey thought the world of his staff and colleagues, and with their support, I feel confident. I think this is what Lindsey would have wanted, and I plan to honor him in this way," she said.

"Now, to Lindsey, I miss you more than I can even put into words. But I'm going to do this. I got it. Thank you."

Long before his decades-long career in the Senate, Graham lost his mother and father within 15 months in his early 20s. He took on the role of raising and caring for his sister, who was 13 years old at the time. He later became her legal guardian.

"Lindsey assured me that he was going to take care of me, he was going to be there for me," she said about her brother in 2014. "He never let me down. Never. I don't see how he did it, to take on the responsibility of raising a little sister."

A preliminary medical report found that Graham died of an aortic dissection caused by arteriosclerotic cardiovascular disease.

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Graham had been a vocal opponent of President Donald Trump but became an ally of his after he won the presidency.

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