Congress leader and author Shashi Tharoor on Saturday said he was "utterly horrified" by the stabbing of novelist Salman Rushdie in New York and expressed concern over whether creative expression can be free and open.

Rushdie was on a ventilator with a damaged liver and may lose one of his eyes after he was stabbed in the neck and abdomen by a man on stage at a literary event in upstate New York.

The Mumbai-born controversial author, who faced Islamist death threats for years after writing "The Satanic Verses", was stabbed by a 24-year-old New Jersey resident identified as Hadi Matar on stage on Friday while he was being introduced at the event of the Chautauqua Institution in Western New York.

"Utterly horrified & shocked by the stabbing of @SalmanRushdie. Wish him a speedy & complete recovery from his wounds, even though, with a sinking heart, I recognize that life for him can never be the same again," Tharoor tweeted.

"A sad day, worse if creative expression can no longer be free & open," he said.

Rushdie was airlifted from a field adjacent to the venue to a hospital in northwestern Pennsylvania where the 75-year-old writer underwent surgery.

The writer has also won the Booker Prize for his novel "Midnight's Children".