NATO member Türkiye on Thursday slammed Greek Cypriot administration’s plans to apply for membership in the military alliance as "unacceptable."

The statement came after Greek Cypriot leader Nikos Christodoulides said on Thursday that they plan to apply for NATO membership when the time is right.

"The Greek Cypriot Administration currently has no application for membership in NATO, but even its attempt is an unacceptable development for Türkiye," Turkish Defense Ministry sources told dpa.

Speaking on the radio, Christodoulides said he is aware that Türkiye is opposed to the move as long as the island remains divided and Turkish Cypriots do not have a say in the decision.

Such an attempt would "disrupt the delicate balance" on the island and "negatively affect the negotiation processes aimed at a solution," said the Turkish Defense Ministry source.

Türkiye recalled that NATO's expansion decisions are taken unanimously and based on members' "national security concerns."

Ankara does not recognize the government in the island's Greek-speaking south.

Christodoulides said Cyprus was expanding its military cooperation with the United States despite Turkish criticism for this reason.

He claimed Greek Cyprus could apply to become a member of NATO once its armed forces receive the necessary training and equipment with U.S. help to bring them up to the standards of the alliance.

The island of Cyprus has been mired in a decadeslong dispute between Turkish and Greek Cypriots despite a series of diplomatic efforts by the U.N. to achieve a comprehensive settlement.

Türkiye is a guarantor country for the Turkish Republic of Northern Cyprus (TRNC) and fully supports a two-state solution on the island based on sovereign equality and equal international status between its two states.

The U.N. is currently working to prepare for a resumption of peace talks between the rival sides.