Negotiations between the United States and the Afghan Taliban for a political settlement to end the protracted war in Afghanistan are stuck over the issue of maintenance of U.S. military bases in the country, according to Waheed Muzhda, a former Taliban official in Kabul who remains in regular contact with Taliban leaders. The “U.S. wants the Taliban to accept at least two military bases, Bagram and Shorabak. The Taliban are not willing to accept it,” Muzhda said, adding the insurgent leaders are unwilling to accept anything more than a nominal number of troops required to secure the U.S. diplomatic mission. US combat forces unwelcomeHigh-level sources in Washington who deal with Afghanistan confirmed to VOA on condition of anonymity that maintenance of certain military bases in Afghanistan was a top priority for the U.S. government.Christopher Kolenda, a retired colonel and former Pentagon adviser who held informal talks this year with the Taliban in Doha, said the insurgent group considers U.S. combat troops an occupying force and wants them out. “Their No. 1 reason for war, their casus belli, if you will, is the occupation. So, they’re not going to just simply say, ‘We’re OK with U.S. combat troops running around Afghanistan.’ Because that’s what they’re fighting to prevent, from their point of view,” he said in an interview with the VOA. He said the Taliban did show some willingness to allow foreign troops to train Afghan forces, but only if a new government formed after a negotiated settlement, that would likely include the Taliban, agreed to their presence. Following Kolenda’s initial contacts with the Taliban, in which retired U.S. diplomat Robin Raphel also accompanied him, Alice Wells, principal deputy assistant secretary for South and Central Asia at the U.S. State Department, met Taliban officials in Doha, Qatar, in July. The meeting was widely believed to be a response to Taliban demands to negotiate directly with the United States, rather than the Afghan government in Kabul, which they consider a “puppet regime.”President Ashraf Ghani has offered the Taliban unconditional negotiations anytime, anywhere. Other Taliban prioritiesPrisoner release is another high priority for the Taliban, according to Muzhda. Reuters reports Taliban officials are preparing a three-to-four member delegation for another round of talks with the United States and want the group's prisoners freed to "meet again for another great cause.” The third major demand, an implementation of Shariah, or Islamic law, is more for the optics. The Taliban accept 80 percent or more of the current Afghan constitution, he said, but think the current constitution was formed under what they term the U.S. occupation of Afghanistan. Khalilullah Safi, an Afghan peace activist who has previously worked with Pugwash Conferences on Science and World Affairs, an international group that has organized several meetings on Afghanistan that included the Taliban, agrees the group largely accepts the Afghan constitution. Cease-fireHopes for peace talks received a boost after an unprecedented cease-fire in June this year, on Eid-al-Fitr, a Muslim holy festival marking the end of Ramadan, led to several days of almost calm in the otherwise volatile country.But violence picked up pace after the cease-fire was over, with the Taliban launching major offensives and putting Afghan security forces under severe pressure. Safi said one reason for the increase in violence was that the Taliban wanted to prove that a fatwa by up to 2,000 Muslim scholars outlawing suicide bombings and denouncing Taliban violence had no impact on the morale of their cadre. Others believe the Taliban want to strengthen their position before possible negotiations with the U.S. US air basesThe Bagram air base, about 60 kilometers north of Kabul, is the largest military base housing U.S. forces in Afghanistan. It includes runways capable of handling aircraft of any size.When high-level U.S. officials such as the secretaries of state or defense visit Afghanistan, their planes land in Bagram, before taking helicopters from there to Kabul for meetings. The latest such trip was when Secretary of Defense James Mattis arrived in Bagram earlier this month. Shorabak, a military base in Helmand province in the south of the country, houses U.S. and Afghan forces. The province produces most of the world’s opium. The drug trade helps fuel the insurgency. It is also one of the most volatile provinces with the highest number of casualties among foreign troops.