Green card
Green card for Belarus
Belarus is not in the green card system, and Greek insurance is not valid there.
Not valid there. You need insurance from that country itself, usually at the border. Ask your insurer first. Own damage cover and roadside assistance apply there only if the territorial limits of the policy say so.
Check the whole trip, with each country on the road · The green card, the full guide
Other countries with the same answer
Sources: Motor Insurers Bureau of Greece, the UK bureau, the Polish bureau.