The ban was first announced ... after the US found ZTE was using front companies
I do support work on equipment legally sold to the DPRK (North Korea) before the latest (ineffective) sanctions were announced under US sponsorship by the UN, are working here they would be shocked.
If the USA realised just how many hundred of it's citizens, and thousands more from other countries employed by well known international companies.
We travel through gateways not used by tourists, we travel openly and some even have motorcycles with them.
But if you check our passports - nothing! The DPRK issues 'loose' visas that are stapled into the passports - not glued. My cell handset has two SIMS - one that international visitors get to make visitor-visitor and international calls with, the other for talking to other numbers as accessed by ordinary citizens. All traces of travel are removed from the passports.
There are fibre optic cables linking major cities to the 'Cloud' but use and access to web sites is strictly controlled.
So much for US 'bans', just another feel good exercise by Washington.