A top Pentagon official has warned that the US would 'consider a range of options' if Pakistan does not seriously address issues related to extremism.

Mark Lippert, a senior Pentagon official, said that "it is Pakistan's responsibility to prevent attacks from its territory on others, including Afghanistan and our forces there."

He made the comments during his testimony before the Senate Armed Services Committee during his confirmation hearing for the post of the Assistant Secretary of Defence for Asian and Pacific Security Affairs.

"If Pakistan does not address these threats, the United States will have to consider a range of options, but it is best when we have Pakistan's co-operation."

He added: "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 the long-term stability of Afghanistan."