South Carolina Senator and US President Donald Trump's close aide passed away on Saturday at the age of 71.According to a statement released by the office of the Republican senator, Graham passed away after a brief and sudden illness.“On the evening of Saturday, July 11, US Senator Lindsey Graham passed away after a brief and sudden illness. Senator Graham's family appreciates prayers at this time and asks for privacy during this incredibly difficult period,” the statement read.Graham represented South Carolina in the US Senate since 2003, winning four terms after serving eight years in the House of Representatives. During more than three decades in Washington, he built a reputation as a defence hawk and a strong advocate of the US military and American engagement overseas.He sought the Republican presidential nomination in 2016 but ended his campaign before voting began. Though initially one of Donald Trump's sharpest Republican critics, Graham later became one of the president's closest allies and a frequent defender.Graham was last seen in Kyiv, where he met Ukrainian President Volodymyr Zelenskyy during an official visit.