Acclaimed professor Joseph Buttigieg, and father of US presidential candidate Pete Buttigieg, has passed away.

South Bend mayor Pete Buttigieg announced his father's passing away through a Facebook post on Sunday afternoon. He was 71.

Joseph Buttigieg was an inspiration to his son.

“We are in mourning today. With his family at his side, Dad passed away peacefully earlier this afternoon. We miss him already but his love of life, and his moral passion, will stay with us forever. As a friend, colleague, thinker, and educator, he touched countless lives, and we hope to find a way to honor his impact later on in the spring."

"The last thing he said to us was, 'it’s been a good trip.' So it has. We love you, Dad," wrote Mayor Buttigieg.

Read: Mayor of Maltese descent enters 2020 US Presidential race

Education Minister Evarist Bartolo described Prof. Buttigieg as a mentor who drove a group of university students 47 years ago.

He was an intellectual and a moral giant- Evarist Bartolo

"He was an intellectual and a moral giant imbued with such a sense of humour. He really was a beacon of hope for all of us those days in the early 1970s," Mr Bartolo told Times of Malta. 

"He believed in the values of social justice and democracy and he campaigned against the 'money can buy you anything' belief. Our country should honour people like him."

Prof. Buttigieg was a professor and translator and served as William R. Kenan Professor of English at the University of Notre Dame until 2017, when he became professor emeritus.

Among other works, he translated and edited the English edition of Antonio Gramsci's Prison Notebooks.

He was raised and began his education in Malta, completing his undergraduate work and a master's degree at the University of Malta. He earned a second undergraduate degree Heythrop College in London, then a doctorate from the State University of New York at Binghamton in New York.

University of Malta professor Peter Mayo said the academic world was poorer without Prof. Buttigieg.

"I lost a great friend, mentor and collaborator. He was also a great commentator on current American politics. The Left is also poorer without Joe."

Author and professor David Ruccio described him as a "left-wing intellectual, critical thinker, rigorous scholar, prolific essayist and frequent speaker around the world."

His son, Pete, only announced last week, that he is jumping into the burgeoning 2020 Democratic field challenging Donald Trump, aiming to become the first openly gay presidential nominee.

Read: In Memoriam: Joseph Buttigieg, Kenan Professor Emeritus of English