Chautauqua, New York - Author Salman Rushdie has been taken off his ventilator and is talking as he recovers from being stabbed in Upstate New York.

In a since-deleted tweet, British-American writer Aatish Taseer said that the 75-year-old novelist was "off the ventilator and talking (and joking)," which was then confirmed by Rushdie's agent Andrew Wylie.

Wylie had previously shared that Rushdie was on a ventilator and could lose an eye after he sustained injuries to his arm and liver in the attack.

The Indian-born Briton, whose novel The Satanic Verses led to death threats from Iran in the 1980s, was about to deliver a lecture at the Chautauqua Institution in Upstate New York when he was attacked.

Hadi Matar (24), the man accused of stabbing him, pleaded not guilty on Saturday to charges of attempted murder and assault in what a prosecutor called a "pre-planned" crime.

A judge ordered him to be held without bail after district attorney Jason Schmidt told her Matar took steps to purposely put himself in a position to harm Rushdie, getting an advance pass to the event where the author was speaking and arriving a day early with a fake ID.

"This was a targeted, unprovoked, pre-planned attack on Mr Rushdie," Schmidt said.

Rushdie was stabbed at least once in the neck and once in the abdomen, according to police, before he was taken to hospital.

His publisher Penguin Random House said they were "deeply shocked and appalled" by the incident.

Labour Party leader Keir Starmer said: "Salman Rushdie has long embodied the struggle for liberty and freedom against those who seek to destroy them.

"This cowardly attack on him yesterday is an attack on those values. The whole Labour Party is praying for his full recovery."

US national security adviser Jake Sullivan said: "Today, the country and the world witnessed a reprehensible attack against the writer Salman Rushdie. This act of violence is appalling."

"All of us in the Biden-Harris administration are praying for his speedy recovery. We are thankful to good citizens and first responders for helping Mr Rushdie so quickly after the attack and to law enforcement for its swift and effective work, which is ongoing."

Vice President Kamala Harris also chimed in on Twitter: "Doug and I were appalled by the attack on author Salman Rushdie this week. People should be able to share ideas without fear – the basis of any free and open society. Violence and hate have no place."

The author lived in hiding for many years in London under a British government protection program after the fatwa.

In 1998, the Iranian government withdrew its support for the death sentence and Rushdie gradually returned to public life, even appearing as himself in the 2001 film Bridget Jones's Diary.

The Index on Censorship, an organization promoting free expression, said the money was raised to boost the reward for Salman's killing as recently as 2016, underscoring that the fatwa still stands.