The leaders of Afghanistan and Pakistan said on Monday they would work to reach a peace deal within six months, while supporting moves for the Taliban to open an office in Doha.
Following talks hosted by British Prime Minister David Cameron, Afghan President Hamid Karzai and his Pakistani counterpart Asif Ali Zardari also urged the Islamists to join the reconciliation process in Afghanistan.
But with no Taliban representative at the tripartite talks and with the militants still refusing to talk to Kabul, analysts said the commitment by the three leaders risked being one-sided.
They had a private dinner on Sunday and then full talks yesterday at Cameron's Chequers country retreat near London, amid growing fears that a civil war could erupt when international troops leave Afghanistan next year.
"They supported the opening of an office in Doha for the purpose of negotiations between the Taliban and the High Peace Council of Afghanistan as part of an Afghan-led peace process," they said in a joint statement.
Karzai had previously shunned the idea of a Taliban office in Doha because of fears that it would lead to the Kabul government being frozen out of talks between the United States and the Taliban.
The joint statement also said that the Afghan and Pakistani leaders had agreed arrangements to "strengthen co-ordination" of the release of Taliban detainees from Pakistani custody.
Afghan peace negotiators have welcomed Pakistan's release of dozens of Taliban prisoners in recent months, a move they believe could help bring militants to the negotiating table.
There was no immediate reaction from the Taliban.
The summit was the third trilateral meeting in a year following meetings in Kabul in July and New York last September – but the first in which Pakistani and Afghan army and intelligence chiefs took part.
Karzai said he hoped to have "very close, brotherly and good neighbourly" relations with Pakistan, which has been regularly accused by Kabul and Washington of helping to destabilise Afghanistan.
Support from Pakistan, which backed Afghanistan's 1996-2001 Taliban regime, is seen as crucial to peace after Nato troops depart - but relations between the neighbours remain uneasy.
Zardari said it was in Islamabad's interests to support the initiative.
"Peace in Afghanistan is peace in Pakistan. We feel that we can only survive together. We cannot change our neighbourhood or our neighbours."
Pakistani political and security analyst Hasan Askari dismissed as "too ambitious" the prospect of securing in six months a settlement to end more than 11 years of war.
Askari said the most realistic achievement would be better co-operation between Afghanistan and Pakistan.