KABUL, Afghanistan — Pakistani intelligence agents and paramilitary forces have helped train Taliban insurgents and have given them information about American troop movements in Afghanistan, a report published yesterday by an American think tank said.

The study by the RAND Corp. also warned that America will face “crippling, long-term consequences” in Afghanistan if Taliban sanctuaries in Pakistan are not eliminated.

It echoes recent statements by American generals, who have increased their warnings that militant safe havens in Pakistan are threatening efforts in Afghanistan. The study was funded by the U.S. Defense Department.

“Every successful insurgency in Afghanistan since 1979 enjoyed safe haven in neighboring countries, and the current insurgency is no different,” the report’s author, Seth Jones, said.

The study, “Counterinsurgency in Afghanistan,” found some active and former officials in Pakistan’s intelligence service and the Frontier Corps — a Pakistani paramilitary force deployed along the Afghan border — provided direct assistance to Taliban militants and helped secure medical care for wounded fighters.

It said NATO officials have uncovered several instances of Pakistani intelligence agents providing information to Taliban fighters, even “tipping off Taliban forces about the location and movement of Afghan and coalition forces, which undermined several U.S. and NATO anti-Taliban military operations.” No timeframes were given.

The report said Pakistan’s intelligence service and other government agencies provided Taliban and other insurgents with training at camps in Pakistan, as well as intelligence, financial assistance, and help crossing the border.

Pakistan’s top military spokesman rejected the findings.