New Delhi, July 13 -- American Senator Lindsey Graham, a key Republican who went from a vocal critic of US President Donald Trump to one of his most loyal allies has passed away at the age of 71.

The South Carolina lawmaker died after a "brief and sudden illness," his office posted on X, early on Sunday. US President, Trump called Graham "one of the greatest people and senators I have ever known" after his demise.

Ukrainian President Volodymyr Zelenskiy said he was "deeply saddened," calling Graham "a true defender of freedom and the values that make our world safer." Graham lost the presidential nomination to Donald Trump in 2016.

Lindsey Graham recently served as chairman of the Senate Budget Committee. Graham also served as a member...