Afghanistan's president told a meeting of more than 600 Afghan and Pakistani tribal leaders that they must find a solution to the region's growing violence.
Pakistan's prime minister acknowledged that Taliban militants cross over their porous border and said most of them are Afghans.
Afghan President Hamid Karzai was speaking on Thursday at a US-backed cross-border jirga, or tribal council, aimed at finding ways to stem Afghanistan's rising bloodshed.
Pakistan President General Pervez Musharraf pulled out of the council at the last moment, citing domestic issues, and tribal elders from the most volatile region in Pakistan's tribal areas are boycotting the four-day event, calling into question how much effect the jirga will have.
"Afghanistan is not under fire alone now," Karzai told the jirga. "Unfortunately our Pakistani brothers are also under fire, and this fire, day by day, is getting hotter."
He repeatedly referred to Pakistanis as the "brothers" of Afghans and said that if the two countries would unite, "This disaster and cruelty in the two nations will be finished in one day."
Karzai spoke passionately of the daily suffering the Afghan people endure as the Taliban attack the government, schools, foreign troops and innocent villagers. He lamented in particular the kidnapping of 23 South Koreans, including 16 women, saying such actions tarnish Afghanistan's image. Twenty-one of the hostages are still alive; two males have been killed.
"It doesn't matter if they kidnap thousands of men, they abducted women!" he said. Referring to other attacks, he said: "They behead women in the name of the Taliban and Muslims in this country. In Helmand, one woman was nailed to a tree. In Zhari, they cut a woman in half. The same thing is happening in provinces near the Pakistan border."
The idea for the jirga was hatched almost a year ago during a White House meeting between US President George W. Bush, Musharraf and Karzai.
Afghan officials have shrugged off Musharraf's decision not to attend, saying that tribal leaders -- the ground-level power-brokers in the restive border region -- were attending the meeting, held in the same white tent where the country's post-Taliban Constitution was hammered out in 2004.
Pakistani Prime Minster Shaukat Aziz said it would be unreasonable for Afghanistan to blame Pakistan for Taliban violence.