ISLAMABAD: Setting terms for renewal of ties with the United States, Pakistan has sought ‘punishment’ for and an ‘apology’ from those responsible for Saturday’s deadly Nato attack on two of its border posts.

The demand, military sources say, was made through a letter sent to Washington earlier this week.

“Nothing short of this will be acceptable,” a senior official said in a background interview with Dawn, adding that Pakistan would otherwise be constrained to “reconsider its partnership in the war on terror”.

Even as the inquiry initiated by the US military is yet to identify who, if anyone, is culpable, a Pakistani general at a media briefing on Tuesday said that International Security Assistance Force chief Gen John Allen was ultimately responsible in his capacity as commander.

However, military officials would not explicitly say if they would like to see his (Gen Allen’s) exit.

Moreover, the US has been asked to clarify why its helicopters returned to attack the post after they had disengaged following contacts between senior Pakistani and Isaf commanders.

Civilian and military leaderships from both sides have been interacting quite regularly to find the way forward, but the mood in Islamabad and Rawalpindi suggests that no progress is likely until the Americans come up with a ‘tangible response’ to Pakistani demands.

Robert Raines, a spokesman for the US Embassy, said discussions were taking place. However, he refused to confirm or deny if any specific demands had been made.

A Pakistani diplomat at the Foreign Office confirmed the demand and said Washington had been categorically told to “stop treating Pakistan as a client state”.

Relations between Pakistan and the US have been on a downward spiral since the start of this year, but the most recent incident has made the much talked about likely breakdown in bilateral ties more imminent.

The government has already expressed its fury by blocking crucial Nato supply route, calling for vacation of the Shamsi airbase by Dec 11 and by pulling out of the Bonn conference on Afghanistan.

Foreign Minister Hina Rabbani Khar, in a telephonic conversation with Italian counterpart Giulio Terzi, said the attack reflected the “callous behaviour” of the US and Nato.

Maj-Gen Ishfaq Nadeem, the Director-General of Military Operations, stepped up the rhetoric earlier in the week by claiming that the attack was deliberate.

TOUGH POSTURE: The manner in which the government moved from its initial reaction to the decision to boycott the Bonn conference and the simultaneous toughening of the tone of Pakistani authorities, observers felt, reflected Islamabad’s dissatisfaction with the US response.

The US has expressed regrets, offered condolences for the fallen soldiers, and opened investigations into the incident, a report on which is expected by Dec 23.

Comments by Gen Martin Dempsey, Chairman of the Joint Chiefs of Staff, in an interview with ITV News that there was “absolutely” nothing to apologise are likely to further inflame the situation.

The military has proposed a set of five options to be exercised in case Washington refuses to accept its mistake, apologise and punish those responsible. The options remain a closely guarded secret, but military sources say some of them are quite extreme.

“We have very few options left with us and we clearly understand their implications,” a Pakistani general said, without elaborating what was being considered.