; to protect such items still in Indian Tribes’ and Native Hawaiian organizations’ possession; and to improve Federal agencies’ implementation of the Native American Graves Protection and Repatriation Act ( 25 U.S.C. 3001 et seq.), the Archaeological Resources Protection Act of 1979 ( 16 U.S.C. 470aa et seq.), and other relevant laws. (c) Responsibilities The interagency working group shall aid in implementation of other provisions of this Act, including regarding voluntary return of Native American items and halting international sales, and shall collaborate with the working groups created pursuant to this Act.