According to news agencies Karzai urged Pakistan to help end Taleban insurgency as his visit was focused on efforts to broker peace with the Taleban after nearly a decade of war.

"The brotherly role of Pakistan ... together with us in defeating extremism and terrorism and working with us to bring stability in both countries would go a long way," Karzai told reporters after meeting with Zardari.

Karzai flew in with a delegation of Cabinet ministers, security chiefs and members of a peace council headed by  Burhanuddin Rabbani.

Earlier, Karzai was accorded a  state welcome  at the Presidential Palace. Prime  Minister Yousaf Raza Gilani, senior ministers, armed forces  chiefs and high  ranking civil and military officials  were   present on the occasion.

Ties between Pakistan and Afghanistan have been hampered by mistrust. Both Afghanistan and the United States say Pakistan is not doing enough to prevent militants from crossing the border to attack American-led NATO troops and Afghan security forces.

Pakistan says it is already stretched fighting its own home-grown Taleban militants.

Analysts say it is reluctant because it sees some pro-Taleban groups like the Haqqani network as a counterweight to growing Indian influence in Afghanistan.

But Islamabad may be more inclined to act after the United States discovered Al-Qaeda leader Osama Bin Laden living in Pakistan. US special forces killed him in a town not far from Islamabad on May 2.

Pakistan, which backed the Taleban government that ruled Afghanistan during the late 1990s, will be crucial to any attempts to stabilize its western neighbor.

Its intelligence services are still believed to have close links with many of the insurgent groups they funded and supported during the war against the Soviet Union and beyond, including the Taleban leadership which is based around the city of Quetta.

Many lower level insurgents also find safe haven in Pakistan's tribal regions.

Pakistan has often been accused of playing a "double game," promising the United States it will go after militants while still supporting some of them, an allegation it denies.

Nevertheless it is seen as an important ally to the United States and other NATO members as they seek to bring the Taleban to the negotiating table.

"As far as Pakistan is concerned, we categorically said that Pakistan wants a peaceful, stable Afghanistan and we are ready to facilitate any Afghan-led, Afghan-owned process of reconciliation and peace," said Foreign Ministry spokeswoman Tehmina Janjua.

Pakistani and Afghan military and intelligence chiefs and other officials, part of a joint commission on reconciliation and peace, are due to hold their first formal talks as part of Karzai's visit.

This summer foreign forces will hand security control in parts of Afghanistan to the national police and army, launching a nearly four-year long process that Western nations and Karzai hope will ensure the departure of all international combat troops by the end of 2014.

Meanwhile in Afghanistan, a suicide bomber detonated his explosives at a memorial service for the assassinated police chief of north Afghanistan on Friday, killing at least four policemen.

The attack appeared to target the police chief of Kunduz province, Sameullah Qatra, whose predecessor in the post was killed by a suicide bomber in March. Qatra was near the bomber but escaped unhurt, his spokesman Sayed Sarwar Hussaini said.