The Afghan and Pakistani leaders are expected to discuss security in Afghanistan after the NATO troop pullout and efforts to negotiate with the Taliban when they meet in Turkey on Thursday Al Arabiya reported
Turkish President Abdullah Gul hosted Afghan President Hamid Karzai and Pakistani Prime Minister Nawaz Sharif over dinner late Wednesday, but the summit officially begins on Thursday.
It is the eighth in Turkey since a regular consultation mechanism was established in 2007 to encourage the neighbours to cooperate in the fight against extremist groups.
The talks will primarily focus on ways to restore peace and promote reconciliation in Afghanistan, a senior Pakistani official told AFP.
Karzai has long blamed Pakistan for sheltering Taliban militants who lead the insurgency against his government.
Last month, Kabul reignited traditional cross-border suspicions by suggesting that Islamabad's spy agency was behind an attack on a Lebanese restaurant in the Afghan capital in which 21 people, including 13 foreigners, were killed.
Taliban insurgents claimed responsibility for the January 17 suicide assault, which was the deadliest attack on foreign civilians since the Taliban were ousted in 2001.
Intelligence officials and high-level military officials from the two countries were expected to hold closed-door talks on the sidelines of the Ankara meeting, the theme of which is "sustainable peace in the heart of Asia."
Karzai, who is due to step down after presidential elections on April 5, is pushing for Pakistan to help start peace talks with the Taliban.
He has demanded progress on talks before Afghanistan signs a security deal with the US that would allow about 10,000 troops to stay in the country after this year.
The supporters of the pact, known as the Bilateral Security Agreement, say it is crucial to Afghanistan's stability after the draw-down of NATO forces by December 31, 2014.
"This agreement is also significant for other NATO allies," a Turkish official said.
"It is hard for other countries to deploy troops in Afghanistan, without the presence of American troops".
On Thursday, Afghanistan released 65 alleged Taliban fighters from jail despite condemnation from the US, which says the men could return to the battlefield to launch strikes against NATO and Afghanistan forces.
The release of detainees from Bagram prison is set to worsen the increasingly-bitter relationship between Kabul and Washington as US-led troops prepare to withdraw.
Pakistan is seen as crucial to peace in neighbouring Afghanistan as it was a key backer of the hardline 1996-2001 Taliban regime in Kabul.
Since the election of Sharif last year, Pakistan has tried to build ties with Afghanistan.
"Pakistan has extended consistent support for peace and reconciliation in Afghanistan," a Pakistani embassy spokesman in Ankara told AFP.
"It remains committed to working with Afghanistan as well as the international community for sustainable peace, stability and development in Afghanistan," he said.
The trilateral summit would "carry forward the process of constructive engagement and leadership exchanges on the evolving situation as well as matters of common interest".
Pakistan, under pressure to curb deadly attacks on its soil and revive its economy, is engaged in talks with its own Taliban.
Observers have been skeptical that Sharif's efforts to negotiate with Tehreek-e-Taliban Pakistan can yield any significant results.