WASHINGTON, May 12: The United States is said to be pressing Pakistan to launch an operation against groups of Al Qaeda fighters concentrated in Waziristan in the tribal areas, but Pakistani authorities are believed to be reluctant to do so.

Reporting this on Sunday, The Washington Post said the Pakistan government’s resistance to the idea of going “after terrorists on its territory is the first major difference to surface in the US-Pakistani alliance against terrorism, which has been surprisingly strong since September.”

The Post report cites unidentified US intelligence analysts as its source, but it also quotes Interior Minister Moinuddin Haider as telling the newspaper in an interview on Friday during his visit to Washington that he was not aware either of large groups of Al Qaeda in Pakistan or of American pressure to do more against them.

The report says Pakistan officials are reluctant for several reasons to launch an attack, including fears of a political backlash, the standoff with India, and lack of confidence in US intelligence assessments of a large build-up of Al Qaeda forces in Pakistan territory. But the report does not refer to the difficulties encountered by the Pakistan government in going into the tribal areas, which had so far been off limit to the military.

Talking to Washington-based Pakistani journalists, Moinuddin Haider had said this was the first time in Pakistan’s history that the army had entered the tribal areas, but pointed out that this had been possible, so far, in the case of only four of the seven tribal agencies concerned. It is not known whether Waziristan is among the areas that are now open to Pakistan troops. The conservative tribal belt has long been known for its independence from Islamabad, and it would be considered as hardly surprising if the central authorities should want to tread warily in the region.

The Post report itself carries a comment from a Pakistani military official, who told the paper that the tribal territory was hostile to US forces and sympathetic to Taliban and Arabs. The official indicated that the US should reconsider before pushing Pakistan “to launch a military assault against thousands of well-armed, religiously motivated people.”

Despite its resistance to the idea of a large-scale operation, the Post says, “the Pakistani government has indicated it understands that the United States may ultimately choose to bomb the pockets of enemy fighters unilaterally, especially if solid intelligence points toward the location of Osama bin Laden or other Al Qaeda leaders.” Haider also told the paper that it had been made “very clear” to tribal leaders that providing sanctuary to Al Qaeda or Taliban “would bring great harm to them.”