WASHINGTON, United States — Republican Senator Lindsey Graham, an influential ally of President Donald Trump and advocate of hawkish US foreign policy, has died unexpectedly aged 71, his office said on Sunday.

Graham was a staunch supporter of the Iran war, and in recent years urged both the Trump and Biden administrations to back Ukraine in its fight against Russia’s invasion.

The South Carolina senator bitterly opposed Trump a decade ago, but ultimately backed the billionaire president as he steadily gained power over the Republican Party.

His support wavered after the January 6, 2021 Capitol insurrection, in which a pro-Trump mob attacked the seat of US democracy, but he later returned to being a staunch ally.

Graham’s office said in a statement on his official
X account that he had “passed away from a brief and sudden illness”. His office later said that the local medical examiner had preliminarily determined Graham’s cause of death to be a tear in his aorta as a result of heart disease.

NBC News reported that emergency services responded to a call for cardiac arrest at Graham’s Capitol Hill home on Saturday night.

Graham had been scheduled to appear Sunday morning on the NBC news talk show Meet the Press.

Trump instead joined the programme and hailed his late ally as a natural-born, hard-working politician skilled at dealing with people from both major US parties.

“He’s a tough one to lose. He was great. He was unique in every way, actually,” Trump said by telephone.

The president said they had actually spoken Saturday evening as Graham returned from a trip to Ukraine, and they made tentative plans to meet on Sunday.

Later, Trump ordered on his Truth Social platform that American flags across the country be lowered to half-staff in mourning.

Graham made a failed bid for the presidency in 2016, warning at the time that Republicans should not back Trump because he was a “race-baiting, xenophobic, religious bigot”.

But Graham later reconciled with Trump and backed his 2024 reelection bid.

Graham was a noted supporter of Israel and had ardently pushed for the United States to attack Iran and overthrow its theocratic government.

Israeli Prime Minister Benjamin Netanyahu said: “Lindsey is a great friend of Israel and a cherished friend of mine.”

Ukrainian President Volodymyr Zelensky said he was deeply saddened by the death of Graham, whom he met in Kyiv as recently as Friday.

“He visited Ukraine ten times during the years of Russia’s full-scale invasion and was here with our people when it was most needed…America and the world have lost a determined leader,” Zelensky said in a
Facebook post.

Graham had recently won a primary election to seek a fourth Senate term in the November midterms.

South Carolina Governor Henry McMaster will have to appoint a successor for the remaining months of Graham’s term while another primary will need to be held.

Graham was first elected to the US House of Representatives in 1994, before being elected to the Senate in 2002.

He was reelected to the Senate in 2008, 2014, and 2020, most recently serving as the chairman of the Senate Budget Committee.

Raised in the town of Central, South Carolina, where his parents ran a restaurant and pool hall, Graham was the first in his family to go to college, according to his biography on the Senate website.

He served as a military lawyer and attained the rank of Air Force colonel, an experience that informed his interventionist stance in foreign affairs.

Graham voted for military action against Iraq in the wake of the September 11, 2001 attacks, and later supported a long-term US presence in Afghanistan.