According to news reports Ambassador to Kabul Zalmay Khalilzad said in a speech in Washington on Monday that Pakistan must eliminate terrorist sanctuaries or the United States would have to step in and do so itself.

Although Pakistan is a key ally in the U.S.-led "war on terror," US forces are not currently allowed to conduct combat operations inside the country.

US military spokesman Lieutenant-Colonel Matt Beevers told a news conference in Kabul it would be inappropriate for him to comment on Khalilzad's remarks.

"That said, our relationship with the Pakistani army in the Federally Administered Tribal Areas remains unchanged," he said.

"I think they are making some significant leaps and bounds there, so we expect that to continue and we look forward to continuing to work in a complementary and parallel fashion as we work on the Afghan side of the border and the Pakistanis work on their side."

Beevers said he was not aware of any plan for US forces to operate in the Pakistani tribal areas, but when asked if US-led forces engaged in "hot pursuit" across the border, he said:

"I don't think it's appropriate to discuss tactics techniques or procedures and make speculations on that."

Asked later to clarify whether US-led forces were confining their activities to Afghanistan and Pakistani troops to their side of the border, he said, "That is correct. Policy remains unchanged."

Pakistan Information Minister Sheikh Rashid Ahmed told the National Assembly in the Pakistani capital of Islamabad on Wednesday that US forces were not needed in the country.

"We will fulfill our responsibilities to fight terrorism and there is no need for the American or coalition forces to do it. This will be unnecessary and we will not allow this," he said.

US forces have referred to their cooperation with Pakistan in the hunt for Taliban and al Qaeda leaders including Osama bin Laden as a "hammer and anvil" approach.

But Afghan and US officials have long complained that Taliban remnants are launching attacks in eastern and southern Afghanistan from the safety of Pakistan.

Last month, Pakistan angrily rejected comments by Khalilzad that senior members of the Taliban and al Qaeda were hiding in Pakistan.

In recent months it has deployed tens of thousands of troops to root out militants in its tribal borderlands. The US-led force hunting al Qaeda and Taliban fighters in Afghanistan will soon reach 15,500, its highest level ever.

Pakistan said it captured or killed about 200 militants in a 12-day battle against about 500 al Qaeda fighters and their Pakistani tribal allies on the border last month.

During that operation a US helicopter gunship mistakenly strayed into Pakistani territory while chasing militants and wounded three civilians, a Pakistani security official said.