Republican US Senator Lindsey Graham died after a brief and sudden illness.

His office issued a statement saying he died Saturday night. “Senator Graham’s family appreciates prayers at this time and asks for privacy during this incredibly difficult period.”

Elected to the Senate in 2002, the South Carolina politician was one of Washington’s most influential voices on foreign policy and a key Trump ally.

He had just returned from kyiv, where he met with Ukrainian President Volodymyr Zelensky on Friday. There were no known health problems before his trip.

In a social media post marking the senator’s death, US President Donald Trump said Graham was a “true American patriot”.

Graham also served as chairman of the Senate Budget Committee.

He was a strong supporter of US support for Ukraine. “Putin will not stop in Ukraine,” he told the BBC in 2023.

“Being weak in Ukraine means losing in Taiwan,” he said.

On his most recent trip to Ukraine, Graham was working on a version of the Russia sanctions bill, which he said would give President Trump “tools to end this war.”

Over the years, Graham clashed with President Trump but became one of his staunchest supporters.

He told the BBC in 2023: “There is a dark side to Donald Trump… and he was a very good president. But I stick with him because I saw what he did,” citing Trump’s record on the US southern border, the assassination of Iran’s Qasem Soleimani and the appointment of conservative judges.