No, we can’t be sure that the magnetic field is in east-west direction and it depends on the material of rod whether it is paramagnetic, ferromagnetic or diamagnetic.

Diamagnetic substances get repelled by a magnetic field therefore if the rod is diamagnetic then it becomes perpendicular to the applied field. Therefore, In this case applied field is in north-south direction

Whereas if the rod is para or ferro magnetic then the rod becomes parallel to the applied field as paramagnetic and ferromagnetic substances get attracted to a magnetic field. Therefore, in this case the magnetic field is in east-west direction.

Therefore, we can’t be sure whether the magnetic field is in north-south or east-west direction