Advisor to Prime Minister on Foreign Affairs Sartaj Aziz said in a statement that, as per Saarc rules, the Summit will not be held if any member country refuses to attend.
He said the Saarc Summit was postponed four times in the past "due to Indian refusal" of its presence, Pakistan Radio reported.
Aziz said that although it is possible to postpone the summit, the Saarc Secretariat has not officially informed the Pakistan government so far.
On Tuesday, India, Afghanistan, Bangladesh and Bhutan wrote to Nepal, the current Chair of Saarc, announcing their pull out.
India said it was pulling out of the November 9-10 summit citing increasing cross-border terrorist attacks in the region and growing interference in the internal affairs of Saarc member-states "by one country" that had created an environment that was not conducive to the successful holding of the 19th Saarc summit.
Afghanistan in its note said: "Due to increased level of violence and fighting as a result of imposed terrorism on Afghanistan, President of Afghanistan Mohammad Ashraf Ghani with his responsibilities as the Commander in Chief will be fully engaged, and will not be able to attend the summit."
Bangladesh said: "The growing interference in the internal affairs of Bangladesh by one country has created an environment which is not conducive to the successful hosting of the 19th Saarc (South Asian Association of Regional Cooperation) Summit in Islamabad in November 2016."
Bhutan noted "the concern of the Royal Government of Bhutan on the recent escalation of terrorism in the region, which has seriously compromised the environment for the successful holding of the 19th Saarc Summit in Islamabad in November 2016".
Sri Lanka, it is learnt, has said that the event would not be possible without India's participation.