classical mechanics - relationship between torque and potential energy for electromagnetism

It is well known that the energy of a magnetic dipole in a magnetic field is taken as $$U = - \bf{m}.\bf{B}$$ The dipole also experiences a torque $$\bf{\tau = m \times B}$$

In classical mechanics, the torque is given as

$$\bf{\tau} = \bf{r \times F}$$ The force is derivable from a potential energy $V$, i.e. $\bf{F = -\nabla}$$V$; you can write the torque as $\bf{\tau = -r \times \nabla}$ $V$.

The dynamics of an object carrying an electric current is governed by the Lorentz force, a velocity-dependent force that cannot be derived from a potential energy function

Source: Daniel R Stump, Am J Phys 66, No. 12 December 1998 pp 1042-1043

Keeping the above quote in mind, is it permissible to use this relationship in the electromagnetic case?