There are historic tensions between EU member Greece and neighbouring Turkey over sovereignty rights in the Aegean Sea and, more recently, over energy exploration and migration.

Turkey, which is a member of NATO but not the EU, is technically eligible to access EU defence industry financing and joint procurement programmes as part of the bloc's 150-billion-euro ($176-billion) Security Action for Europe (SAFE) initiative.

But Greek Prime Minister Kyriakos Mitsotakis said late on Wednesday that his country would not allow Turkey to take part in the defence scheme if it continued to threaten war against Greece and question its sovereignty in the Aegean Sea.

"Greece will not allow it," the conservative leader told Skai TV.

Turkey maintains a longstanding threat of war should Greece unilaterally expand its territorial waters in the Aegean.

Mitsotakis pointed out that all 27 EU members would have to agree before Turkey could access SAFE funds.

"Unanimity is required," he stressed.

His comments came hours after Germany said it had approved the delivery of Eurofighter jets to Turkey.

Turkey had been in talks for several years on buying 40 of the aircraft, which are constructed by a consortium from Germany, Britain, Italy and Spain.

- Conditions -

The Typhoon jets are to be built in Britain and London is leading the negotiations.

All members of the consortium must sign off on the sale and Germany, which has clashed with Turkey over Israel's war on Gaza, had objected until now.

After Germany gave the green light to the sale, the Turkish and British defence ministers signed a preliminary agreement in Istanbul on Wednesday for the delivery of the jets.

Mitsotakis said that while Greece could, if deemed necessary, block Turkey from accessing SAFE funds, it could not actually prevent the Eurofighter deal.

It could, however, set conditions.

"Turkey is a large country with a strong defence industry," he said.

"And if someone believes they can block any purchase of defence equipment by Turkey, they are deeply ignorant. It has never happened. It cannot happen.

"What can happen, however, is that we make our European allies aware that there will be contingencies and conditions regarding the way these aircraft will be delivered, potentially used and supported in the future," he said.

The EU has launched a raft of initiatives aimed at raising up to 800 billion euros to help member countries bolster their defences.

SAFE is a 150-billion-euro financing package designed to strengthen European defence capabilities and reduce dependence on NATO and the United States.

The scheme offers low-interest loans for procurement and can include third countries with whom the EU has a security and defence partnership, such as Turkey.