A protracted war in neighbouring Afghanistan is Pakistan’s “nightmare scenario", the country’s national security adviser said Monday.
Moeed Yusuf also slammed relentless blaming of Islamabad for the rapidly deteriorating security situation in Afghanistan.
The US should take the lead to get the Afghan government and the Taliban back to the negotiation table, Mr Yusuf said.
He said Pakistan was pushing the Taliban to return to negotiations but its influence is waning as the insurgent group gains more ground in Afghanistan.
Pakistan has not even been able to convince the Taliban to reopen the border crossing at Spin Boldak in south-eastern Afghanistan, which the insurgent force captured last month, Mr Yusuf said.
In their sweep through Afghanistan, which began with start of the final withdrawal of US and Nato troops in April, the Taliban have gained control of strategic and lucrative border crossings, including the Spin Boldak crossing with Pakistan.
Last weekend the Taliban closed the crossing after Islamabad demanded that Afghans crossing to the Pakistani side have a passport and a Pakistani visa, something that had not previously been required.
The Taliban accused Pakistan of imposing the new rules to please Kabul and President Ashraf Ghani.
They closed the border, insisting that Pakistan reinstate an earlier lax policy under which the thousands who cross daily were rarely required to show even local identity cards.
As a result, thousands of Afghans and Pakistanis are stuck at the border and hundreds of trucks loaded with perishable goods have been waiting to cross.
As the August 31 deadline for the final withdrawal of US and Nato troops from Afghanistan approaches, Mr Yusuf called for “a reinvigorated, re-emphasised, rejuvenated effort to try and get Afghan political actors … in one room … to get to a settlement of how to move forward".
“Anything but an inclusive political settlement means a protracted conflict, through which instability will likely spill over into Pakistan,” he said. “So our nightmare scenario is a protracted conflict.”
Mr Yusuf said Pakistan, which already hosts about two million Afghan refugees, has not got the resources to absorb a new influx.
The government fears that will happen if fighting continues and the sides do not return to the negotiating table.
The Taliban’s onslaught defies statements by their political leadership in Qatar calling for talks.
The insurgent force has shown no sign of wanting to negotiate, instead pressing ahead on the battlefield, sweeping through five provincial capitals in less than a week.
Mr Yusuf accused Afghanistan of making a scapegoat of Pakistan, blaming it for the Taliban advances.
He demanded evidence of accusations by Kabul at a recent UN Security Council meeting that 10,000 fighters were crossing from Pakistan into Afghanistan.
Mr Yusuf attacked the performance of Afghanistan’s National Defence and Security Forces in those areas where they abandoned districts, occasionally crossing into Tajikistan, Iran or Pakistan to escape the advancing Taliban.
“We are told that over a trillion dollars were put into Afghanistan and much of that into the ANDSF to prepare the army and the security forces," he said.
"What is going on with this well-equipped and trained force?”