Turkey's defence minister has warned against Nato members forming alliances outside of the organisation, after France and Greece signed a five-year pact.
On Saturday, Hulusi Akar said such alliances risked “harming” and “shaking” the intergovernmental military alliance, of which Turkey is also a member.
Greece and France signed a strategic military and defence pact in September, which includes an order for three French frigates worth €3 billion.
Greek Prime Minister Kyriakos Mitsotakis has said the agreement will allow the two countries to come to each other's aid in the event of an external threat.
But Mr Akar warns the move will harm the alliance.
“Given that we are inside Nato, everyone should know that the search for various alliances outside of it will both cause harm to Nato and our bilateral relations, and shake confidence,” he said.
Greece announced last year that it would overhaul its military, including the hiring of personnel and a major military procurement programme that has led to the country buying 18 French Rafale fighter aircraft.
The defence deal with France includes a mutual assistance clause.
This states that the two sides will come to each other’s aid “with all appropriate means at their disposal, and if necessary with the use of armed force, if they jointly ascertain that an armed attack is taking place against the territory of one of the two”.
Greece and Turkey have been at odds over their continental shelves and maritime boundaries.
Relations between the two nations have long been strained over territorial issues in the Eastern Mediterranean, including air space, energy, the status of some Aegean Islands, and the status of Cyprus.
They re-launched exploratory contacts on their disputes earlier this year and Mr Akar said he had recently held a constructive meeting with his Greek counterpart.
“We had positive, constructive talks with the Greek defence minister. We expect to see positive results from these talks in the period ahead,” Mr Akar said.
Separately, Mr Akar said that “technical work has been launched” on obtaining Viper F16 jets from the US, as well as modernising warplanes that Turkey already has.
The US this week did not confirm comments by Turkish President Recep Tayyip Erdogan that Washington had made an offer to Ankara for the sale of F-16 fighter aircraft.