A purported Taliban statement on Wednesday said the hard-line militia would open "new fronts" in its fight against foreign forces in Afghanistan and threatened "severe" action in the coming days.
The written statement -- issued amid a deadly upsurge in violence in southern Afghanistan -- said Afghan police and army should stop helping "foreign occupation forces" and seek forgiveness from the Taliban or face more casualties.
"There will be a manifold increase in mujahedeen operations in the coming few days. The operations will strong and severe and new fronts will be opened against the enemy up and down the country," said the statement.
The statement was issued in the name of the media committee of "Afghanistan's Islamic Emirate" -- a reference to the name of the country during the Taliban's rule.
It was not possible to independently verify its authenticity. The statement gave no specifics about how the Taliban would step up its fight.
"Every person in Afghanistan is witness to the defeat and weakness of American soldiers. This international community will also witness the same thing in the coming days," the statement said, without elaborating.
The threat came as Afghan and coalition soldiers reclaimed the second of two towns that had been overrun in recent days by the Taliban in southern Helmand province.
Fighting in the militia's former southern heartland has escalated sharply this year. More than 800 people have died in violence over the past two months, mostly militants.