Salman Rushdie is "pulling through" and is on the "road to recovery, his former wife and celebrated TV personality Padma Lakshmi and his agent said on Sunday, two days after the Mumbai-born author was stabbed in New York in what US authorities described as a "targeted, unprovoked, preplanned" attack.

Rushdie was taken off a ventilator on Saturday and could talk after the best-selling author was stabbed on stage at a literary event in New York state on Friday.

Rushdie, 75, and Chennai-born Lakshmi married in 2004 and got divorced in 2007. Lakshmi, 51, who is herself an author and the host of the hit culinary TV show TopChef, was Rushdie's fourth wife.

"Relieved @SalmanRushdie is pulling through after Friday's nightmare. Worried and wordless, can finally exhale. Now hoping for swift healing, she said in a tweet.

The New York Times reported that Rushdie's agent Andrew Wylie said, The road to recovery has begun. It will be long; the injuries are severe, but his condition is headed in the right direction.

Rushdie, 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, the US national of Lebanese origin, on stage on Friday while he was being introduced at a literary event of the Chautauqua Institution in Western New York.

"@SalmanRushdie off ventilator and talking! Continued prayers from all @chq," Chautauqua Institution president Michael Hill said in a tweet on Saturday night. Rushdie's agent Wylie confirmed to the US media.

Rushdie was put on a ventilator after he was stabbed by Matar.

Earlier on Saturday, Matar pleaded not guilty to charges of attempted murder and assault at a brief court appearance where he was denied bail.

Matar was charged with attempted murder and assault in the stabbing of Rushdie and he pleaded not guilty. He made his appearance in court, wearing a black-and-white striped jumpsuit and handcuffed.

Chautauqua County District Attorney Jason Schmidt provided the details of Rushdie's injuries in court during Matar's arraignment Saturday afternoon.

The author's injuries include three stab wounds to the right side of the front of his neck, four stab wounds to his stomach, a puncture wound to his right eye and chest, and a laceration on his right thigh, according to the county prosecutor.

This was a targeted, unprovoked, preplanned attack on Mr Rushdie, Schmidt alleged.

Matar faces up to 32 years if convicted of both charges, Schmidt said.

The attack on Rushdie drew shock and condemnation from world leaders and literary stalwarts.

US President Joe Biden said in a statement on Saturday that he and First Lady Jill Biden were "shocked and saddened" to learn of the "vicious" attack on the author.

"Salman Rushdie -- with his insight into humanity, with his unmatched sense for story, with his refusal to be intimidated or silenced -- stands for essential, universal ideals. Truth. Courage. Resilience. The ability to share ideas without fear. These are the building blocks of any free and open society. And today, we reaffirm our commitment to those deeply American values in solidarity with Rushdie and all those who stand for freedom of expression," Biden said.

"We, together with all Americans and people around the world, are praying for his health and recovery. I am grateful to the first responders and the brave individuals who jumped into action to render aid to Rushdie and subdue the attacker," he added.

UN Secretary-General Antonio Guterres said he is "appalled" to learn about the attack on Rushdie. "The Secretary-General was appalled to learn of the attack on renowned novelist Salman Rushdie," a statement issued on Friday by his spokesperson said.

"In no case is violence a response to words spoken or written by others in their exercise of the freedoms of opinion and expression," Guterres said, conveying his wishes for Rushdie's early recovery.

European Union foreign policy chief Josep Borrell strongly condemned the attack on Saturday night.

International rejection of such criminal actions, which violate fundamental rights and freedoms, is the only path towards a better and more peaceful world , Borrell tweeted.

Rushdie lived in hiding and under police protection for years after late Iranian leader Ayatollah Ruhollah Khomeini put out a fatwa in 1989 calling for his death in retribution for his book The Satanic Verses.

A report in The New York Times said according to prosecutors, Rushdie was stabbed roughly 10 times in the premeditated attack.

"In court, prosecutors said that the attack on the author was premeditated and targeted," the report said, adding that Matar travelled by bus to the "intellectual retreat in western New York and purchased a pass that allowed him to attend" the talk "Rushdie was to give on Friday morning".

Rushdie, the author of 14 novels, was knighted in 2007 for services to literature.