How will articles being imported from outside the EU be controlled for compliance?
I assume that you refer to a filled packaging and that you (industry) buy a packaging or a food packaged by an importer. You examine the documentation certifying the compliance with EU rules (DoC and SD). In case of doubt, you have to check migration as for any European producer. The official enforcement authorities will check compliance by analysing the foodstuffs and examining the DoC and SD (no difference to European products).