“We attach the highest priority to the safety and security of our weapon systems. If any shortcoming is found, it would be immediately rectified,” Defence Minister Rajnath Singh told parliament on Tuesday.
The missile that landed in Pakistan was accidentally released during routine maintenance and inspection operations, he said.
India revealed on Friday that the missile had been accidentally fired at about 7pm last Wednesday.
Pakistan has asked for a joint probe into the incident and demanded clarification on India's safety mechanism to prevent accidental launches.
New Delhi’s response came hours after Islamabad summoned its top diplomat in Pakistan to lodge a protest against “the unprovoked violation of its airspace”.
No casualties were reported but Pakistan's military claimed that the projectile damaged civilian property.
Military experts have previously warned of the risk of accidents or miscalculations by the nuclear-armed arch rivals, who have fought three wars.
India has started a high-level inquiry into the accident, Mr Singh said.
“I can assure the House that the missile system is very reliable and safe,” he said, without specifying which missile had been accidentally launched.
“Moreover, our safety procedures and protocols are of the highest order and are reviewed from time to time.”
Agencies contributed to this report.