A system for mounting wall panels to an existing wall structure, includes wall panels, each formed by a main wall panel section and at least two bent end sections; fastening extrusions, each including a base section adapted to be secured to the existing wall structure and a rigid wall extending at an angle therefrom; and a latch arrangement for securing the wall panels to the rigid wall, the latch arrangement including a latch housing, a movable latch member mounted in the latch housing for either engaging within through openings of respective ones of the rigid wall and the bent end sections, or applying a force on each bent end section positioned against a respective rigid wall, and a force application member for moving the movable latch member into a position to cause locking of respective ones of the rigid wall and the bent end sections.