WASHINGTON (Reuters) - The Taliban has created a “resilient insurgency” in Afghanistan and will likely maintain or increase the pace of its attacks this year, the Pentagon said on Friday.

U.S. Sergeant Eric McWilliams (L) and other soldiers from the 101st Airborne Division, 506th Infantry Regiment, 2nd Battalion, 4th Platoon prepare to clear a cave in a suspected Taliban area near the Pakistani border in Khost province May 21, 2008. REUTERS/Rafal Gerszak

In a report to the U.S. Congress, the Pentagon also singled out the safe havens for insurgents in Pakistan’s border areas as the biggest threat to security in Afghanistan.

It said Washington and its allies had made substantial progress since ousting the Taliban from power after the September 11, 2001 attacks on the United States but lasting success would take time and require much more than just military means.

“The Taliban regrouped after its fall from power and have coalesced into a resilient insurgency,” the report said.

In a sign of the increasing anxiety in Washington and other Western capitals about rising violence in Afghanistan, Congress ordered the comprehensive report when it approved the Pentagon’s annual budget for this year.

The report said NATO and U.S. forces had killed some key insurgent leaders and removed sanctuaries inside Afghanistan.

“Despite these setbacks, the Taliban is likely to maintain or even increase the scope and pace of its terrorist attacks and bombings in 2008,” it said.

“The Taliban will challenge the control of the Afghan government in rural areas, especially in the south and east. The Taliban will also probably attempt to increase its presence in the west and north,” the report added.

The 72-page report offered some of the starkest U.S. comments yet on Pakistan’s border areas.

TRIBAL AREAS

“The greatest challenge to long-term security within Afghanistan is the insurgent sanctuary within the Federally Administered Tribal Areas (FATA) of Pakistan,” it said.

U.S. officials say the sanctuaries have flourished in recent months as Pakistani security forces have stopped pressuring insurgents while the government tries to strike peace deals with local tribes.

The U.S. commander of NATO forces in eastern Afghanistan said this week insurgent attacks there rose by 40 percent this year and Defense Secretary Robert Gates blamed that rise partly on a lack of pressure on the Pakistani side of the border.

The United States has some 32,000 troops in Afghanistan. Some 14,000 serve as part of a 53,000-strong NATO force charged with stabilizing the country while the remaining 18,000 perform missions ranging from training to counter-terrorism.

The report painted a positive picture of the Afghan army but said the police had faced problems.

“Generally, police development has been hindered by a lack of reform, corruption, insufficient U.S. military trainers and advisors and a lack of unity of effort within the international community,” it said.

In addition, no comprehensive strategy exists to tackle the drug trade in Afghanistan, the world’s top supplier of opium.

“While progress has been made in some areas, overall counter-narcotics efforts in Afghanistan have not been successful,” the report said.

“There is a clear nexus between narcotics and the insurgency in Afghanistan that threatens U.S. gains in Afghanistan and the region,” it added.