Step 1: Think of the needle as a tiny magnet.
A magnetic needle is a small dipole with a north pole and a south pole separated by a short distance. Each pole feels a force from the surrounding field.
Step 2: What torque does.
In any external field, the two opposite poles get pushed in opposite directions, which tends to twist the needle to line it up with the field. This twisting effect is the torque, given by $\vec{\tau} = \vec{m}\times\vec{B}$.
Step 3: The case of a uniform field.
If the field is the same everywhere, the forces on the two poles are equal and opposite, so they cancel and give no net force. Only torque remains.
Step 4: The case of a non-uniform field.
When the field is stronger at one pole than the other, the two pole forces no longer cancel. That leaves a net force on the needle, in addition to the twisting torque.
Step 5: Conclusion.
In a non-uniform field the needle feels both a net force and a torque. \[ \boxed{\text{both force and torque}} \]