Graham's office announced on Saturday that the senator had died following what it described as a "brief and sudden illness."

Graham's office announced on Saturday that the senator had died following what it described as a "brief and sudden illness."

The office of late Sen. Lindsey Graham has released the preliminary findings from the District of Columbia's Medical Examiner, identifying the longtime South Carolina Republican's cause of death after he died suddenly over the weekend at age 71.

In a statement released Monday, Graham's office said the Medical Examiner's preliminary examination found the senator died from "Aortic Dissection due to Arteriosclerotic Cardiovascular Disease."

According to the statement, "The death certificate will be PENDING until all the toxicological and microscopic testing are finalized and at that point the death certificate will be updated to reflect the cause of death and appropriately classify the manner of death."

Graham's office announced on Saturday that the senator had died following what it described as a "brief and sudden illness."

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

Emergency responders were dispatched to Graham's Capitol Hill home Saturday night after reports of a "cardiac arrest," according to NBC News. The cause of death had not previously been made public.

The senator had returned from a trip to Kyiv, Ukraine, shortly before his death. On Friday, he met with Ukrainian President Volodymyr Zelenskyy, where the two discussed proposed US sanctions on Russia.

President Donald Trump said during an appearance on NBC's Meet the Press that he had spoken with Graham by phone just hours before his death and said the senator did not indicate he was seriously ill.

"So what makes it even stranger is that I got a call last night sometime. You know, the early evening, maybe in the sevens. And he called and he said, we're all set for the Save America Act. He was pushing the Save America act like crazy. He got back, said he just landed from Ukraine and said, that's a long trip to make. And he said - he sounded a little tired, but perfect, but a little bit tired. Had a right to be when he was a worker. He was really a worker," Trump said.

"But he sounded great, actually... He said he was tired, but he wanted to pass the Save America Act. And I said, well, we're going to get it done, Lindsey. We're going to get it done. I'll see you like soon," Trump added.

Graham served in the US Senate since 2003 and had represented South Carolina for 23 years.

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