WASHINGTON: Religious extremists operating along the Pak-Afghan border pose a direct threat to Pakistan’s existence, the commander of US forces in the region, General David Petraeus, warned on Wednesday.

During a Senate Armed Services Committee hearing on US President Barack Obama’s new strategy, Gen. Petraeus also vowed to take the fight to insurgents in both Afghanistan and Pakistan.

He did not explain how he planned to do so but last President Obama said that the United States would pursue ‘high-value’ terrorist targets inside Pakistan but would consult Islamabad before doing so.

Also last week, Obama’s National Security Adviser Gen. James Jones indicated that the US would continue drone attacks inside Pakistan as they had proven ‘effective’ against the militants.

Gen. Petraeus told the senate panel that the Taliban and al-Qaeda groups based in the border area were ‘an ever more serious threat to Pakistan’s very existence.’

The Pakistani military, he said, had stepped up operations against the militants but more action was needed.

The general noted that the situation in Pakistan was closely linked to that of Afghanistan, and praised President Obama’s new plan for developing a regional approach to resolve the issue was a step in the right direction.

Gen. Petraeus acknowledged that the militants in Afghanistan were growing in strength but vowed to fight them ‘relentlessly and aggressively.’

But Gen. Petraeus and top Defence Department official Michele Flournoy were greeted with sceptical questions from senators about how willing the Pakistani government is to fight extremists hiding in Fata.

Committee Chairman Carl Levin warned that he did not agree with the administration’s contention that progress in Afghanistan depended on success on the Pakistan side of the border.

Afghanistan’s future should not be tied totally to the Pakistan government’s decisions, he said, adding that he remained sceptical about Pakistan’s ability to secure its border.

‘I remain sceptical that Pakistan has either the will or the capability to secure their border,’ he said.

Senator Levin earlier urged Pakistan to prove it’s willing to take on extremists within its own borders before the US delivers financial aid or weapons to Islamabad. The senator said he did not believe the United States can buy stability in Pakistan.

Senator Levin said he would support economic and military aid only after he saw that the Pakistani government understood that it’s in its own interest to battle its internal insurgent threats. So far, he said he is not convinced.

‘If I thought we could buy stability, I would buy it,’ the Democrat told reporters. ‘I have no reluctance in purchasing stability if it’s effective. But I don’t think it’s effective unless the recipient of the support sees where the threat is to them. I think otherwise it can backfire.’

Gen. David Petraeus, however, disagreed with Senator Levin’s scepticism about additional US aid to Pakistan, insisting that the US assistance would help Pakistan fight the insurgents.

Flournouy, a top Pentagon policy official, also called for expanded aid to Pakistan, though she said, ‘military and economic support will be limited if we do not see improvements in Pakistani importance.’

The question of how to treat Pakistan has emerged as a key disagreement between the Obama administration and Senator Levin, one of his party’s most influential voices on defence.

Senator Levin has been largely supportive of the Obama administration’s new strategy and backed the decision to send about 21,000 additional troops to Afghanistan.

Gen. Petraeus warned that strengthening insurgents threaten not just Afghanistan and Pakistan, but other nations in the region, including India, and raise the chances of terrorist attacks in the United States.

And he called expanded operations against al-Qaeda in Pakistan ‘imperative’ in weakening that effort, and defended Pakistan’s efforts.

‘The Pakistani military has sacrificed much during this campaign,’ he said.

Gen. Petraeus said insurgent success in Afghanistan, where violence has increased, was directly linked to dissatisfaction among the Afghan people with their government’s performance and frustration with government corruption.