Afghan President Hamid Karzai is to hold key talks with Pakistan's newly elected government on Monday, searching for direct communication with Taliban insurgents to end 12 years of war.

It is Karzai's first visit to Islamabad in 18 months and signals a desire by both countries to overcome distrust and hostility as 87,000 NATO combat troops prepare to leave Afghanistan next year.

Elements of the Pakistan state are widely accused of funding, controlling and sheltering the Taliban, but Islamabad says publicly it will do anything to stop the fighting in Afghanistan.

Karzai was furious when the Taliban opened a liaison office in Qatar in June, billed as a precursor to talks with US officials but perceived as a self-styled embassy for a government in waiting.

He is now travelling to Islamabad in an effort to harness Pakistani support to find a direct channel of communication with the militants.

Karzai insists that his government should take a central role in any peace talks, but the Taliban refuse to open contact with him or his appointed negotiators, dismissing him as a US puppet.

"The first item with Pakistan will be the peace negotiations," Karzai told a news conference in Kabul on Saturday.

It will be Karzai's first meeting with Pakistan's Prime Minister Nawaz Sharif, who took office in June after winning elections.

He praised Sharif for having "all the right intentions for stability and peace", but conceded that previous visits had not achieved the goal of improving security in Afghanistan.

Karzai believes Taliban safe havens in Pakistan are the main cause of increased violence in his country.

"I will travel to Pakistan hoping to get a result out of it. I'm hopeful, but not sure, I will only go with hopes, and wish they materialise," he told reporters.

Afghan government peace negotiators, who will accompany Karzai, have called for the release of the most senior Taliban figure detained in Pakistan, former deputy leader Abdul Ghani Baradar.

Pakistan released 26 Taliban prisoners late last year, including the militants' former justice minister Nooruddin Turabi.

Afghan officials believe the releases can encourage former detainees to talk to the Kabul government, although observers say there is little evidence those hopes have been realised. Several prisoners are also understood to have returned to the battlefield.

Analysts say Pakistan can facilitate Taliban peace talks and help with logistics, but does not have the power to force the insurgents to the negotiating table against their will.

"Peace and stability in Afghanistan are in Pakistan's vital interest," the Pakistani foreign ministry said Sunday.

"President Karzai's visit will impart a strong impetus to ongoing efforts for an enhanced relationship... and enable the leadership on both sides to further strengthen their joint endeavours in the pursuit of durable peace, stability and prosperity."