Thousands of protesters held a rally Friday to demand that neighbor Greece recognize the existence of a Macedonian minority.
The protest is tied to a long-standing name dispute between the two countries. Athens is demanding that Macedonia change or modify its name, fearing a potential territorial claim against its own northern region called Macedonia.
Negotiations on the name, mediated by the United Nations, have been deadlocked for years.
Organizers of Friday's rally in Macedonia's capital Skopje said the protest was attended by some 8,000 people, and included veterans of the 1946-49 Greek civil War who fought with defeated rebel forces.
The Greek-born veterans say they were excluded from post civil war amnesties allowing exiled civil war fighters to return to Greece.
"National identity cannot be deleted by decree. It is our civil right to declare ourselves as Macedonians and we will never give up from our identity," parliament speaker Trajko Veljanovski said, addressing the rally.
Earlier this week, Macedonian Minister Nikola Gruevski wrote a letter to his Greek counterpart, Costas Karamanlis, to demand recognition of the minority.
Athens denies the minority's existence and officials there have referred only to "Slavic-language speakers" living in northern Greece.
On Friday, Karamanlis accused Gruevski of attempting to undermine the name negotiations.
"There is no 'Macedonian minority' in Greece. It never existed," Karamanlis wrote in response to Gruevski.
"Your letter is a great distance away from the efforts being made in the (name) negotiations for improved bilateral relations, and raises groundless and nonexistent issues."