By Steve Holland, Akanksha Khushi, Thomas Derpinghaus and Tim ReidWASHINGTON, July 12 (Reuters) - Republican U.S. Senator Lindsey Graham, a one-time vocal critic of Donald Trump who went on to become one of the president's staunchest allies, died late on Saturday from a heart ailment caused by hardening of the arteries, his office said on Sunday. He was 71.In an interview with Reuters, Trump said he spoke to Graham "minutes" before the South Carolina Republican was taken ill and ruled out any foul play.

Firebrand US Senator Lindsey Graham has died at the age of 71 after a 'brief and sudden illness.'

Republican senator had served in the Senate since 2003 and was a sharp critic of Trump before becoming one of his most loyal backers

South Carolina Senator and US President Donald Trump's close aide passed away on Saturday at the age of 71.