Remove nav menu or menu item

I try to remove a nav menu programmatically but I didn’t find the way to do it. I knwo how to create it but I don’t know how to delete it…
I’ve got the menu name and I wan’t to delete it like in wp admin panel but programmatically.

Or I want to delete all the menu item inside it.

Finally the answer is simple:

$menu_name="your menu";//name,id,slug
wp_delete_nav_menu($menu_name);