Lindsey Graham, the US senator and prominent ally of Donald Trump, has died.

The 71-year-old, who was a Republican representative for South Carolina, died on Saturday "from a brief and sudden illness", his office said.

The statement continued: "Senator Graham's family appreciates prayers at this time and asks for privacy during this incredibly difficult period."

Emergency services responded to a call for "cardiac arrest" at Mr Graham's Washington DC home on Saturday night, according to police scanner audio obtained by our US partner, NBC News.

The senator, scheduled to appear on NBC News' Meet The Press on Sunday, had just returned from a trip to Ukraine, where he met with President Volodymyr Zelenskyy in Kyiv on Friday.

In a social media post, Mr Zelenskyy said that he was "deeply saddened" by the news.

He went on: "Lindsey was a true defender of freedom and the values that make our world safer. He had been working on important initiatives that could help bring peace closer, including stronger sanctions against Russia. America and the world have lost a determined leader.

"Our condolences go out to Lindsey's family, loved ones, and everyone who had the privilege of working alongside him."

Mr Graham was elected to the US Senate in 2002, and was seeking a fifth six-year term in November.

He was a key Republican voice on defence and international affairs, with his website saying he "consistently pushed for outcomes ​in the War on Terror ​that protect our long-term national security interests".

US president pays tribute

Mr Trump described Mr Graham as "one of the greatest people and Senators I have ever known" in a post on Truth Social.

He added: "He was always working, and was a true American Patriot. Lindsey will be greatly missed!!! DETAILS AND ARRANGEMENTS TO FOLLOW. So sad!"

Mr Graham was initially critical of Mr Trump when the New York businessman moved into politics - but later became one of his staunchest supporters.

He was one of the few Republicans able to remain a key ally for the US president despite publicly disagreeing with him.

In 2025, Mr Graham criticised the decision to pardon the Trump supporters who stormed the US Capitol on 6 January 2021.

Former UK prime minister Boris Johnson said he was "shocked and saddened" to hear of Mr Graham's death, describing him as "a great American patriot and friend of the United Kingdom".

"He was a redoubtable defender of Western values and he worked tirelessly for peace in Ukraine. He will be much missed," Mr Johnson added.

Israeli Prime Minister Benjamin Netanyahu paid tribute to Mr Graham, posting on X: "Lindsey understood that the security of Israel and America are inseparable.

"He devoted his life to defending America, strengthening our alliance and standing up for the free world.

"Israel has lost one of its greatest friends. America has lost a great patriot. I have lost a beloved friend."

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South Carolina governor Henry McMaster also paid tribute on X, saying his family was "devastated" by the death of the "irreplaceable" politician.

"The fiercest of fighters for South Carolina and America - and a loyal and steadfast friend," he wrote. "We grieve with [Graham's sister] Darline, his family and his devoted staff."

(c) Sky News 2026: US senator and Donald Trump ally Lindsey Graham dies