Singh emphasised that Jammu and Kashmir was, and would remain, the integral part of India.
Sharif's remarks came days after Indian Army chief Gen Dalbir Singh warned Pakistan-sponsored violence in Jammu and Kashmir and other areas could trigger short and swift wars.
"If there is any subject related to Jammu and Kashmir and Pakistan it is how the parts of Pakistan Occupied Kashmir (PoK) can be again included in India.
"That means the area, which after 65-66 years, even after being part of Jammu and Kashmir, is under illegal possession of Pakistan," the minister said.
His comments came after the Pakistan army chief called Kashmir warned of "unbearable damage" in case of a "long or short" misadventure.
"If the enemy ever resorts to any misadventure, regardless of its size and scale - short or long - it will have to pay an unbearable cost," he said in his address at a special event in Rawalpindi to mark the 50th anniversary of the 1965 war with India.Armed forces of Pakistan are fully capable of dealing with all types of internal and external threats, may it be conventional or sub-conventional; whether it is cold start or hot start. We are ready," Sharif said.
The statements follow days of bickering after the Pakistani government decided to cancel a meeting of its national security adviser with his Indian counterpart, citing New Delhi's refusal to allow an expanded agenda and a meeting with Kashmiri leaders.
India-Pakistan relations are at a low, with the two sides regularly trading fire over the Line of Control in Kashmir in recent months.
On Monday, a civilian was killed and four others were injured in Pakistani shelling along the LoC in Jammu and Kashmir's Poonch district.