Afghanistan's interior minister says there may be between 10,000 and 15,000 Taliban fighting inside his country, and the insurgent group is operating across about 17 provinces.
Mohammad Hanif Atmar offered a rare estimate of the size of his government's most organized and potent opponent during a visit to Washington.
A large delegation of senior Afghan officials was in the U.S. capital this week, along with a delegation from Pakistan.
Both groups were weighing in as the new Obama administration forms a new strategy for the war in Afghanistan and a related policy for Pakistan.
Afghan officials say they told their hosts that a new strategy must include better cooperation from Pakistan, where Taliban and other militants have command operations.