Extremism that plagues Afghanistan has crept across the border into Pakistan, President Karzai of Afghanistan said yesterday at the opening of a meeting between more than 600 Pakistani and Afghan tribal leaders. Mr. Karzai expressed hope that the four-day gathering in Kabul would help address security problems in the border regions — where resurgent Taliban fighters have stepped up attacks and Al Qaeda is feared to have regrouped.

The head of Pakistan’s delegation, Prime Minister Aziz, said the future of Pakistan and Afghanistan are intertwined, and that instability in one country affects the other.

But he also said Afghanistan needed to address its own insurgency problems and not cast blame on Pakistan.

“Afghanistan is not yet at peace within itself. The objective of national reconciliation remains elusive,” Mr. Aziz said. “They can’t blame anyone else for failing to achieve this objective that lies at the heart of their malaise.”

The effectiveness of the meeting was questioned because President Musharraf pulled out at the last moment, and tribal elders from the most volatile region in Pakistan’s tribal areas are boycotting the event.

General Musharraf told Mr. Karzai on Wednesday that “engagements” in Islamabad, the Pakistani capital, prevented him from attending.

Officials in Islamabad said yesterday that the government had considered imposing a state of emergency because of security threats, citing deteriorating security in the volatile northwest near the Afghan border, but decided against it.

Afghan officials had shrugged off General Musharraf’s decision not to attend, saying that tribal leaders — the ground-level power-brokers in the restive border region — would still attend the meeting, held in the same white tent where the country’s post-Taliban constitution was hammered out in 2004.