Attacks against US forces unacceptable: Pentagon

"Attacks against US and coalition personnel are unacceptable. It is Pakistan`s responsibility to prevent attacks from its territory on others, including Afghanistan and US forces there. If Pakistan does not address these threats, the US will have to consider a range of options, but it is best when we have Pakistan`s cooperation," Pentagon official James Miller said.

"My understanding is that US forces in Afghanistan are authorised to act in self-defence when they are under attack," Miller told lawmakers in written answers submitted to the Senate Armed Services Committee, during a confirmation hearing for the post of Undersecretary of Defence for Policy.

Miller was responding to a question on his understanding of the rules of engagement for US troops in Afghanistan who were subjected to cross-border attacks from the Haqqani network or other insurgent forces on the Pakistan side of the Afghanistan-Pakistan border.

"I also understand that ISAF and USCENTCOM (US Central Command) are working with the Pakistanis to improve cross-border coordination and have conducted several tripartite meetings with Afghan and Pakistani security forces in recent months," he said.

Miller said the ability of violent extremist groups to find support and safe haven in Pakistan poses a significant threat to US forces, the NATO mission, and Afghanistan`s long-term stability.