New Delhi, Aug 21 (PTI) The upcoming Indo-Pak NSA-level talks appeared to be virtually off today with the two countries locked in a confrontation over Kashmiri separatists leading to a blame game.

Drawing a redline, India made it clear to Pakistan that a meeting between the separatists and Pakistan's National Security Adviser Sartaj Aziz, who is scheduled to arrive here on Sunday for the talks with his Indian counterpart Ajit Doval, was unacceptable.

Pakistan reacted strongly to insist that it would not depart from the "established past practice" of interacting with separatist Hurriyat leaders, rejecting India's advice not to go ahead with their meeting with Aziz.

India hit back accusing Pakistan of trying to evade its commitment to engage in a substantive discussion on terrorism as had been agreed between Prime Minister Narendra Modi and his Pakistani counterpart Nawaz Sharif in Ufa (Russia) last month.

It said that Islamabad's insistence on meeting Hurriyat leaders as a pre-condition was a complete departure from the Ufa understanding. Moreover, India has always held the position that there are only two, not three, stakeholders in the bilateral relationship.

Unilateral imposition of new conditions and "distortion of the agreed agenda cannot be the basis for going forward," External Affairs Spokesperson Vikas Swarup said.

With the two sides sticking to their positions, the likelihood of talks between the NSAs on Sunday and Monday appear to be extremely remote. But neither side was formally calling off the talks. .