U.S. officials are adding 63 American Indian reservations across the Midwest and West to an initiative that seeks to return millions of acres of land to tribal ownership.

The move comes as the Interior Department warns the $1.9 billion effort to return up to 3 million acres of land to tribes is running out of time and money.

The Associated Press obtained details in advance of a planned Tuesday announcement. Reservations in 16 states are joining the program.

It's the result of a legal settlement with American Indians led by Elouise Cobell of Montana, who said the U.S. mismanaged trust money held on behalf of hundreds of thousands of Indians.

Since 2013, the U.S. has paid $742 million to restore 1.5 million acres to tribal control.