President Donald Trump commented Tuesday on the death of the late Republican Sen. Lindsey Graham, stating that doctors briefed him on the senator's heart condition, which he described as "almost undetectable." Trump also expressed skepticism about the FBI's involvement in the probe into Graham's death.

During a meeting with Iraqi Prime Minister Ali al-Zaidi, Trump responded to a reporter's question about the FBI reportedly being seen at Graham's home. FBI Director Kash Patel had previously stated the bureau was assisting local authorities in the death investigation.

"I've watched all the medical reports, I've had the doctors from the White House come in and explain what happened," Trump said. "And this is something that is almost undetectable and if it happens, there's not much you can do about it." He added that Graham had sometimes mentioned having a "bad back," suggesting it could have been a sign of the condition.

Graham died in Washington, D.C., one day after returning from Kyiv, where he met with Ukrainian President Volodymyr Zelenskyy. Preliminary findings from the District of Columbia's Office of the Chief Medical Examiner identified the cause of death as an aortic dissection due to arteriosclerotic cardiovascular disease, though the official cause remains pending further testing. An aortic dissection is a critical condition where a tear occurs in the inner layer of the aorta, the body's main artery.

Trump also stated that Graham's father died of the same condition, a claim that Politico reported in 2015 was inaccurate, stating his father had died of a massive heart attack. Fox News senior medical analyst Dr. Marc Siegel explained that an aortic dissection can manifest rapidly and may be difficult to recognize.

Mehmet Oz, a cardiothoracic surgeon and administrator for the U.S. Centers for Medicare and Medicaid Services, offered a medical explanation of the condition. Using a paper towel roll as a prop, Oz demonstrated how a tear in the aorta can disrupt blood flow, potentially leading to cardiac tamponade and rapid death. He noted that there is limited time for medical intervention in such cases.

Graham's sister, Darline Graham, was appointed by South Carolina Gov. Henry McMaster to serve the remainder of her brother's term in the Senate, which concludes on Jan. 3, 2027. She was scheduled to be sworn in on Tuesday.