Extract xz archive on Raspbian Stretch, show progress

To extract xz archive at first I need "xz-utils" package to be installed:

sudo apt-get install xz-utils

Now I can extract xz archive using:

unxz -v kali-2017.2-rpi3-nexmon.img.xz

By default it will delete the original file. If I want to keep original file I would like to add "k" to the command:

unxz -kv kali-2017.2-rpi3-nexmon.img.xz