ANKARA - Turkey will hold an Afghan peace summit from April 24 to May 4 meant to jump-start efforts to end Afghanistan's war and sketch out a possible political settlement, Turkish authorities said on Tuesday.The summit includes the United Nations and Qatar as part of a U.S.-backed push to advance talks ahead of a May 1 deadline for the withdrawal of foreign troops from Afghanistan.Turkey's foreign ministry said the Afghan government and the Taliban insurgent group would attend the summit. However, the Taliban said they had not yet committed to attending on that date. "Our internal discussions regarding this have not completed yet, the date can't be specified until our discussions are completed," said Mohammad Naeem, the Taliban's spokesman.On Monday the Taliban had said it was unwilling, based on timing, to attend talks in Turkey initially scheduled for April 16."Participation in the conference and its agenda have been the subject of extensive consultations with the Afghan parties," Turkey's foreign ministry said.Referring to the Taliban, U.N. spokesman Stephane Dujarric told reporters in New York: "We understand deliberations are still going on and we very much hope they will participate." President Joe Biden has decided to withdraw U.S. troops from Afghanistan by Sept. 11, 2021, the anniversary of the 9/11 attacks that sparked the foreign presence, three sources familiar with the decision told Reuters on Tuesday.It was not immediately clear how the Taliban would respond to troops staying past next month, after signing a deal with the Trump administration in February 2020 that stipulated foreign forces would leave by May 2021.The Turkey summit is meant to end the conflict, pave the way to a "just and durable" political settlement and "accelerate and complement" intra-Afghan negotiations in Doha, a Turkish foreign ministry statement said.Officials worry that violence in the country will surge if an agreement is not reached soon.The U.S. envoy for Afghanistan, Zalmay Khalilzad, has been traveling the region to drum up support for a ceasefire and peace settlement that could include an interim government.Turkish Foreign Minister Mevlut Cavusoglu has held a series of calls with counterparts including the United States and some Gulf Arab nations over the past week to invite them to the talks and drum up support.