Kumar, who will be flying tomorrow to the Pathankot Indian Air Force base for an on-the-spot assessment, said solving the conspiracy behind the attack is a "very big challenge" but recalled how the agency had in the past established the identity of culprits in many blind cases.
"It's a very challenging case and a lot of investigation needs to be done. Therefore, I am not fixing any deadline to the case but we will try to complete the probe soon," Kumar said.
He, however, refrained from naming the terror group responsible for the attack, saying "Let us work first. We will be able to establish everything once we have some evidence to support our claims. The case has to be proved before the court of law and therefore I will refrain from making statements on speculation."
Also Read
NIA had yesterday registered three cases in connection with the brazen terror strike, including the murder of a taxi driver by suspected terrorists, kidnapping of a Superintendent of Police rank officer and attack on the IAF base on the intervening night of January one and two.
"We will ask them (Pakistan) to give us the voice samples once we identify these people," he said.
The terrorists had made several calls from the local mobile phone of a jeweller Rajesh Verma to places in Pakistan including Bahawalpur where they spoke to their handlers as well as family members, official sources said.
The NIA chief said Central Forensic Science Laboratory (CFSL) team was already assisting the 20-member agency team that is camping in Pathankot after the news of terror strike broke in the morning of January two.