WASHINGTON — 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 co-operation from Pakistan, where Taliban and other militants have command operations.

Afghan and Pakistani officials met separately this week, as well as in three-way sessions with U.S. hosts.