Iran wants to inflict "pain" on Western forces in Afghanistan but its support for the Taliban has so far been small and insignificant, US defence secretary Robert Gates said today.
"We do have evidence of Iranian involvement, particularly in the western part of Afghanistan," Mr Gates told lawmakers at a hearing.
"It is still a relatively small -- making a relatively small and not significant contribution to the Taliban effort."
Shia Iran is not a comfortable ally of the hardline Sunni Taliban but analysts say Tehran may be providing some support to tie down and irritate US forces in Afghanistan.
Mr Gates said Iran was partly restrained by its desire to have friendly relations with the Afghan government.
"But there is no question they would like to inflict pain on us," Mr Gates said.
"And so I think trying to target their efforts in ways that are aimed at (Nato forces) and not at the Afghan government is what they're trying to do but it's still at a very modest level."
Reuters