"The group of British soldiers will arrive in Tunisia to assist in the training of the Tunisian military controlling the borders," Belhassen Oueslati said.
He added that the instructors will teach the local border guards to operate specialized military equipment and will not directly participate in any military operation.
Libya has been in a state of turmoil since its longtime leader Muammar Gaddafi was deposed and killed in 2011. IS, which is outlawed in many countries including Russia, seized a pocket of Libyan territory centered in Gaddafi's hometown of Sirte in November 2014.
In early February, Tunisian Defense Minister Farhat Horchani said the construction of the 196-kilometer (122-mile) protective wall all along the border with Libya had been completed in order to prevent IS militants from reaching Tunisia.
The wall's construction was announced after the June 2015 attack on a tourist resort in the city of Sousse that resulted in nearly 40 deaths.