Around 1,600 delegates, representing Afghans across the political and social spectrum, are attending the so-called peace jirga which wraps up on Friday in a massive tent in Kabul's southeastern suburbs.
"If we fail to open a window for peace through this jirga we will never be able to open the gate for peace in the future," said Qiamuddin Kashaf, acting head of the Ulema Council of Afghanistan and a deputy chairman of the jirga.
"The delegates are determined to make this jirga a success, this is our common voice that we won't leave here failed," he told reporters on Thursday.
The aim of the jirga is to formulate a plan for President Hamid Karzai to approach militant leaders, including who and how, for negotiations that could lead to an end to the near nine-year conflict.
Karzai referred in his opening speech to his "Taliban brothers" and implored them to stop destroying their homeland.The jirga was a key part of his re-election platform last year, although Karzai has said that he will not talk to Taliban leaders who are affiliated with al-Qaeda or who do not renounce violence.
His Western backers, particularly the United States and NATO, have expressed support for the jirga as a milestone in Afghanistan's political maturity after the overthrow of the Taliban regime in a 2001 US-led invasion.The escalating insurgency is concentrated in the southern provinces of Helmand and Kandahar, where international forces are building up with the aim of squeezing the militants into neutrality by year-end.
The Taliban have said they will not open negotiations until all foreign forces leave Afghanistan.There are 130,000 troops under US and NATO command leading the battle against the insurgents, with another 20,000 due to be deployed by August, most to Kandahar, main theatre of operations.The Taliban were not invited to the jirga though organisers said they would not be refused if they did turn up.
But the insurgents launched an attack on the opening session of the jirga on Wednesday, with a suicide squad firing rockets near the jirga tent until two of them were shot dead and one taken into custody, authorities said.