The Taliban will "never" negotiate with Afghan authorities until U.S. and NATO forces leave the country, a spokesman for the group said Sunday, again rebuffing an overture for peace talks from President Hamid Karzai.

Clashes and airstrikes, meanwhile, killed 14 suspected Taliban on Saturday, capping a week that saw more than 270 people killed in insurgency-related violence.

Karzai said Saturday he would be willing to meet personally with Taliban leader Mullah Omar and give militants a position in government in exchange for peace. But Taliban spokesman Qari Yousef Ahmadi repeated a position he announced earlier this month, saying there would be no negotiations until U.S. and NATO troops withdraw from Afghanistan.

"The Taliban will never negotiate with the Afghan government in the presence of foreign forces," Ahmadi told The Associated Press. "Even if Karzai gives up his presidency, it's not possible that Mullah Omar would agree to negotiations. The foreign forces don't have the authority to talk about Afghanistan."

Karzai's peace overture came as insurgency-related violence continued to climb. Thirty people, mostly army soldiers, were killed in a suicide bomb attack on a military bus Saturday in Kabul.

More than 270 have died in violence since last Sunday — 180 of them militants, according to an Associated Press tally of figures from Afghan and Western officials.

In the latest violence, insurgents ambushed a convoy of foreign troops in eastern Paktia province on Saturday. After a brief gunbattle airstrikes were called in that killed 11 militants, a provincial police official said Sunday on condition of anonymity because he was unauthorized to speak publicly.

The U.S. coalition said it was not involved in the battle, and NATO also did not have any information on the incident.

Another battle in Paktia between police and militants on Saturday left one suspected insurgent dead, the police official said.

In neighboring Ghazni province, coalition forces fought with insurgents, killing two Taliban on Saturday in Andar district, said deputy provincial police chief Mohammad Zaman.

Ghazni is the province where the 23 South Korean hostages were captured in July. Two of the hostages were killed, and the rest were later released after talks between the Taliban and a South Korean government delegation.

Military officials said they expected a spike in violence during the holy month of Ramadan based on an increase in attacks last year during the same period.

The death toll this week includes more than 165 militants killed during two battles between the Taliban and joint Afghan-coalition forces, and the 30 soldiers and civilians killed in the Kabul suicide bombing.

Militant attacks and military operations have killed more than 4,600 people so far this year, most of them insurgents, according to the AP count.