ISLAMABAD (Reuters) - Pakistan will need months to prepare for a ground offensive against the Taliban in their South Waziristan stronghold on the Afghan border, a senior army commander said on Tuesday, citing equipment shortages. US President Barack Obamas visiting special envoy to Afghanistan and Pakistan, Richard Holbrooke, said Washington was trying to expedite delivery of the equipment requested by the Pakistani army, including helicopters and parts. After briefing Holbrooke on its operations against militants, Lieutenant-General Nadeem Ahmed told reporters the army was trying to create the right conditions for a full-blown offensive in the rugged South Waziristan region by imposing a tight blockade on entry and exit points, and by pounding militant targets from the air. Its going to take months, and possibly beyond the coming winter, Ahmed said, when asked how long it would take for those conditions to be met and for the army to move in on the ground. He said military leaders would decide on the timing. Some US officials have expressed concern that Pakistan will lose momentum if it puts off the offensive for too long. With US troop strength growing in Afghanistan, Washington wants Pakistani forces in control of the area to prevent Taliban fighters from crossing the border unimpeded as they did during US operations in Afghanistan in 2001. Ahmed said the army was now focused on choking off supplies to militants in South Waziristan. All the entries and exists are being controlled so nothing moves in, nothing moves out, he said, with the possible exception of supplies moved by foot through mountain passes. Ahmed said Pakistan was attacking militants with planes, helicopters and artillery with the goal of wearing them out before ground forces go in. Once you feel that the conditions are right and you have been able to substantially dent their infrastructure and their fighting capacity, then you go in for a ground offensive, Ahmed said. That may happen in winter, or even beyond, probably. Ahmed said the army was currently short of the right kind of equipment to mount a large-scale ground operation, and urged Holbrooke to help Pakistan obtain Cobra attack helicopters. Holbrooke said the Cobra was hard to come by because the aircraft was no longer being built. Ahmed said many of the Pakistani militarys helicopters were still being used in an offensive against militants in the Swat valley, and that they needed maintenance before being sent into Waziristan. A US military official, speaking on condition of anonymity, said the Pentagon was very aware of the counter-insurgency needs of the Pakistani military. We know they have shortfalls and were working hard to get them the equipment as soon as possible, the official said. In addition to Cobras, Ahmed cited shortfalls of protective gear, intelligence-gathering and night-vision equipment, and precision weapons. If we can really get these shortfalls addressed promptly, the operation will be that much more effective, he said. The apparent death of Baitullah Mehsud, the Taliban leader, may hasten a ground offensive in South Waziristan, Ahmed said. US and Pakistani officials have been heartened by signs of a rift between Taliban factions following the CIAs Aug 5 missile strike on Mehsud. Ahmed told Holbrooke that Mehsuds death had a psychological impact on his group, a loose federation of 13 factions known as Tehrik-e-Taliban Pakistan (TTP). But Ahmed said the Taliban remained a potent force that could still do something substantial.