"Ridiculous and inconsistent," was the verdict of hardline separatist leader Syed Ali Geelani on Zardari's shock categorisation of the two-decade old Kashmiri insurgency against Indian rule.
"Kashmiris are not terrorists. They are freedom fighters," Geelani said.
Since 1989, more than 43,000 people have been killed in the armed struggle in Indian Kashmir which has always enjoyed Pakistan's implicit backing
Zardari came out with the "terrorist" tag in a recent interview with the Wall Street Journal -- apparently the first time that any Pakistani leader has referred to the Islamic militants in Indian Kashmir in such a way.
He also said that India had never been a threat to his country.
Both views appeared to run counter to those of Pakistan's powerful military, which has regarded its nuclear-armed neighbour as an existential threat since the creation of the two countries after independence in 1947.
And among Kashmiri separatists they amounted to little short of heresy.
"It shows how ignorant he is about the sub-continent's history," Geelani said of Zardari who, as the widower of former premier Benazir Bhutto, came to power in September after the civilian government in Islamabad ousted president Pervez Musharraf.
The main militant alliance in the region, the United Jehad Council, said the president's statements had only served to rub salt into the wounds of the Kashmiri people.
"It is also equivalent to stabbing the freedom-loving nation in the back," the council said in a statement that stressed how Kashmiris had only taken up arms as a "last resort".
In the northern town of Baramulla, slogan-chanting Kashmiri youths burnt effigies of Zardari and called on him to step down as president.
India has long accused Pakistan of sponsoring the Islamist insurgency in the part of the divided Himalayan territory controlled by New Delhi.
Pakistan denies the claim but has often spoken in support of those fighting for what it calls the right to self-determination in Kashmir, while state television runs daily segments on alleged Indian atrocities in the region.
Kashmir has been disputed by India and Pakistan since the partition of the subcontinent in 1947.
The two neighbours have twice waged war over the Muslim-majority region, which is divided by a Line of Control.
Maulana Abbass Ansari, a moderate separatist and leading Shiite cleric, said Zardari's comments would have no concrete impact on the fight against Indian rule.
"We have nothing to do with Zardari. Our freedom struggle will continue," Ansari said.
Militant violence had fallen sharply in Kashmir after India and Pakistan launched a peace process in 2004.
But that process has begun to stagnate and in recent months the Kashmir Valley has witnessed the largest anti-India protests for years.