ISLAMABAD -- A key gathering was underway Monday in Islamabad with four countries -- Afghanistan, Pakistan, China and the United States -- hoping to lay the roadmap to peace for the war-shattered Afghan nation.

The meeting comes as Afghanistan's battlefield losses are mounting and some parts of the country are under constant threat from Taliban gunmen. Taliban representatives have not been invited to the talks, vowing to talk only to the U.S. and not to the government in Kabul.

As the gathering got under way, host Pakistan -- seen as key to bringing the warring Taliban factions to the table -- cautioned of the difficulties ahead.

Sartaj Aziz, adviser to the Pakistani prime minister on foreign affairs, warned against prematurely deciding which Taliban factions are ready to talk, urging instead "confidence building" measures to get even the recalcitrant Taliban to the negotiating table.

But analysts and participants say much of the hope for progress toward peace rests with Pakistan, which is accused of harbouring some of the fiercest factions of the Taliban, including the Haqqani group, a U.S.-declared terrorist organization. Pakistan says its influence over the Taliban is overrated.

"Even at the best of times they (Taliban) didn't listen to us," Aziz told The Associated Press earlier. "Look at Bamiyan," he said, referring to the Taliban's destruction in the summer of 2001 of some of the world's most precious statues of Buddha. The Taliban blew up the statues, ignoring the roars of dissent, including from Pakistan.

The Taliban have stepped up their insurgency since the withdrawal of NATO-led combat troops from Afghanistan a year ago, testing government forces that are forced to spread their resources across the country. But while the fight intensifies, the insurgents rarely hold territory they take for more than a few days and are often driven back by Afghan security forces, sometimes with the support of U.S. airstrikes.

Aziz refused to say whether Pakistan has a list of Taliban representatives prepared to enter into peace negotiations. The existence of such a list was announced Sunday by Javid Faisal, deputy spokesman for Afghanistan's Chief Executive Abdullah Abdullah.

At the start of Monday's conference, Aziz urged that participants avoid the media and work toward finding ways to get all the Taliban to talk peace. He said the Islamabad gathering needs to define the "overall direction of the reconciliation process" and goals that would create a "conducive environment for holding direct talks between the Afghan government and Taliban groups."

After Aziz's televised remarks, the meeting proceeded behind closed doors into afternoon hours.

Meanwhile, a breakaway Taliban group said Monday it was ready for talks. The faction, which emerged following the revelation last year that the Taliban leader and founder Mullah Mohammed Omar had died two years ago, is believed to be relatively small and its absence from the battlefield is unlikely to be a game changer.

In Afghanistan, the Taliban have recently been on the offensive in southern Helmand province bordering Pakistan, threatening key towns, including the capital of Lashkar Gah. Most of the world's opium is produced in Helmand, which along with other contraband helps fund the insurgency.

In the province's Sangin district, the Taliban besieging the local army base for days before reinforcements, backed by U.S. air strikes and British military advisers, were sent in to repel the attackers.

As the prospect of a peace dialogue grows, the Taliban can be expected to step up their fight in order to ensure they join any peace dialogue from a position of strength.

Imtiaz Gul, whose Center for Research and Security Studies has delved deeply into the Afghan conflict and Pakistan's decades-old involvement, says Pakistan has significant leverage with the Taliban, led by Omar's replacement Mullah Akhtar Mansoor.

Militants in both countries are allied, and getting rid of the Haqqanis, for example, could unleash a violent backlash inside Pakistan where the army has been fighting for several years to defeat a coalition of militant groups largely based in its border areas with Afghanistan, Gul said.

That battle has been brutal with thousands of Pakistani soldiers killed and wounded and thousands more Pakistani civilians killed in deadly retaliatory suicide attacks by the militants.

Gul said last month's trip by Pakistan's army chief Gen. Raheel Sharif, who travelled to Afghanistan unaccompanied by the country's powerful ISI intelligence agency, long considered the force behind the Taliban, was a signal the military was ready to move away from past practices and centre future policy decisions only at the army headquarters.

Changes won't come quickly, says Gul, "but important for us is to turn the page (from supporting militants) and I think Gen. Raheel Sharif has turned that page."

Though the Taliban were not invited to Monday's talks, a senior Taliban official, who spoke on condition of anonymity fearing exposure and capture, told the AP that two Taliban delegates, currently headquartered in Qatar, will meet "soon" with China's representatives. The meeting, which will also include Pakistan, is to be held in Islamabad, said the official.

Still, there seems little to no chance for early peace talks between the Taliban and the Afghan government.

The Taliban, struggling to consolidate their leadership council following Omar's death, have drawn their line in the sand: no official talks with Kabul on a peaceful end to their protracted and bloody war until direct talks can be held with the United States.

"We want talks with the Americans first because we consider them a direct party," the Taliban official said in a face-to-face interview with the AP.

The Taliban want recognition of their Qatar office under the banner of the Islamic Emirate of Afghanistan, the name they used when they ruled Afghanistan until they were ousted by the U.S.-led coalition in 2001. They also want the United Nations to remove the Taliban from its wanted list and they want their prisoners released from Afghan jails.

Afghan President Ashraf Ghani wants no part in giving the Taliban official recognition.

Maulvi Shazada Shaeid, a representative on Afghanistan's High Peace Council, tasked with seeking peace with the Taliban, said the distance between the two sides is vast, holding out little hope for peace.

"In the current situation, it is not possible to bring peace," he said.

Kathy Gannon is special regional correspondent for Afghanistan and Pakistan. Associated Press writers Mirwais Khan in Kandahar, Afghanistan, and Lynne O'Donnell in Kabul contributed to this report.