The NATO secretary general has acknowledged that the US and its allies underestimated the difficulty of the mission when they launched the war in Afghanistan, Press TV reported.
The US and its allies underestimated the difficulty of defeating the Taliban militants and that is why it is taking a long time to establish peace and stability in Afghanistan, Anders Fogh Rasmussen said in an interview on Monday.
"I believe the international community underestimated the mission in Afghanistan," he added.
Rasmussen's remarks come on the eve of an international conference on Afghanistan in Kabul.
He also stated that the US-led forces will probably face a rise in casualties since the Taliban will fight fiercely to defend their strongholds when they are attacked.