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You can use either an EU ID card or Passport to enter the EU (Proof of EU citizenship).
According to the Migration and Social Inclusion Code (Article 4(6) of Law 4251/2014), entry to Greece may not be refused to persons who are proved to be Greek nationals or nationals of an EU member state, even if not in possession of a passport or other travel documents.
However, Albanian or North Macedonian authorities might need a passport for exit checks.