Macedonia's premier urged neighboring Greece on Monday to recognize a Macedonian ethnic minority — escalating a long-running dispute between the two Balkan countries.

Macedonia contends that members of its minority in Greece fled government persecution before and during the aftermath of World War II and the Greek 1946-49 Civil War.

Greece denies the existence of a minority. Greek officials have referred only to "Slavic-language speakers" living in northern Greece.

"You and I cannot change history. But with good will, we can make up for past wrongdoing and help our citizens seek a better future," Prime Minister Nikola Gruevski wrote in a letter to Greek counterpart Costas Karamanlis.

"Several hundred thousand (people) were forced to leave their homes and country of birth. But those people, decades later ... can still not reclaim their property, are banned entry to Greece and cannot seek dual citizenship," Gruevski wrote.

It was the latest twist in the long-running identity dispute between the two countries. Greece wants Macedonia to change or modify its name, warning of a potential territorial claim against its own region of Macedonia.

Greece's government spokesman issued a sharp response to the letter, accusing Gruevski's government of attempting to disrupt the name negotiations.

"This letter is the latest in a series of statements, unacceptable in tone and content, made by various officials in Skopje," spokesman Theodoros Roussopoulos said.

Greece blocked Macedonia's bid to join NATO earlier this year, after talks involving the United Nations failed to end the disagreement. Macedonia gained independence from Yugoslavia in 1991.