Sīstān ( Persian : سیستان ) , or Sakastan , is a historical region in modern-day eastern Iran ( Sistan and Baluchestan Province ) , southern Afghanistan ( Nimruz , Kandahar and Zabul ) and the Nok Kundi of Balochistan , western Pakistan .
Sīstān ( Persian : سیستان ) is a border region in eastern Iran ( Sistan and Baluchestan Province ) and southern Afghanistan ( Nimroz , Kandahar and Zabul provinces ) .