He was unable to obtain the necessary documents from the military unit.

Dane Karl Balderson, who joined the international legion of Ukraine, was told to leave the country.

He reports this on his Facebook page.

"today I received a message from the Ukrainian immigration center !!
the reason is lack of paperwork for your work in Ukraine
i have been in 3 different military units in ukraine and this has been a long struggle for me to get my parpir work for them now I have been told I have to leave the country!! WTF
I dont do that this is simply too fuckt o that a military unit cannot figure out how to send necessary parpir ! if I go home to Denmark without military papers I can get up to 10 years in prison!!
I have no interest in leaving Ukraine
I think this is completely ridiculous
and disrespectful they will have to arrest me and throw me out of the country before I leave !!
For the past 2 months, I have been in dialogue with all units about my military work in Ukraine!
it's war and the military is busy with other work and then I have to be thrown out of the country?
this must be a fucking joke"

Recall that Karl Balderson helped to liberate cities in the Kyiv region captured by the Russian army, and also evacuated civilians.