US Defence Secretary Robert Gates has said Taliban and Al Qaeda are using Pakistan's tribal areas particularly north Waziristan to regroup, a problem the US is trying to address with Islamabad.

"I would say the Taliban and Al Qaeda have been able to use the areas around particularly north Waziristan to regroup and it is a problem. We are working together with Pakistan to address that problem," Gates told mediapersons at the Pentagon.

Responding to queries whether the safe havens and training camps used by Al Qaeda and Taliban in Afghanistan can be taken out by the US if Pakistan was either unable or unwilling to do so, Gates only confirmed the problem, without getting into the specifics of the rules of engagement along the restive border.

The trouble along the Pakistan-Afghanistan border is meriting considerable attention in US Congress with many top lawmakers saying that it is well within international law for hot pursuit and that it is futile for a country to talk about sovereignty without having control of large areas.

Gates also said the North Atlantic Treaty Organisation-led alliance force anticipated increase in violence and were prepared for such an eventuality in the spring.

"We anticipate that they would try and increase it further this spring. And as the NATO defence ministers discussed in Seville, we made a commitment that the spring offensive in Afghanistan would be our offensive. We have extended a brigade, so we have plussed up our own troops. And we are determined to take these guys on and push them back" he added.