In general, most countries require the importer to have a permit. This is required for EU countries. You will need to obtain a phyto-sanitary certificate to include with the shipment, and there are requirements for inspection and treatment.
Below are pix of the search for requirements for Belgium, as an example, when you go to the USDA PCIT website
In the case of Belgium, it required that the cuttings be attached to the plant, that the plant be inspected 2-3 times over the course of 30-60 days, and then removed from the plant, and shipped with an import permit and a phyto-sanitary certificate. Each of those inspections costs $$.

This website will also give you a headache.