The Afghan Taliban say they will not participate in a peace process with Kabul's government until foreign forces in Afghanistan stop attacking their positions and leave the country.

In a statement Saturday, a Taliban spokesman says the insurgents "reject" peace talks between representatives of the Taliban and Afghan authorities.

Direct face-to-face talks were expected to take place in the Pakistani capital Islamabad next week. Afghan officials have characterized the meeting as the first real step in a peace process aimed at ending the war, now in its 15th year.

The Taliban statement, however, says the insurgents will not take part.

It accuses the U.S. of boosting troop numbers, carrying out air strikes and night raids on residential compounds. It also says Kabul's forces have escalated their fight against the insurgents.