Greek Prime Minister Kyriakos Mitsotakis on Saturday announced a "robust" arms purchase programme and an overhaul of the country's military amid tension with Turkey in the eastern Mediterranean.

"The time has come to reinforce the armed forces... these initiatives constitute a robust programme that will become a national shield," the PM said in a keynote address in the northern city of Thessaloniki.

Mitsotakis said Greece would acquire 18 French-made Rafale warplanes, four multi-purpose frigates and four navy helicopters, while also recruiting 15,000 new troops and pouring resources into the national arms industry and cyber-attack defence.

New anti-tank weapons, navy torpedoes and airforce missiles will be secured, the PM said.

The programme, which includes upgrades of another existing four frigates, is also designed to create thousands of jobs, he said.

More details on the cost of the programme and origin of the weapons purchases will be announced at a news conference Sunday, a government source told AFP.

Mitsotakis is believed to have hammered out the programme after talks with French President Emmanuel Macron during a southern European leaders summit in Corsica this week.

In contrast to other EU and NATO allies, France has strongly backed Greece in its burgeoning showdown with Turkey, as well as Cyprus.

Macron has told Turkish counterpart Recep Tayyip Erdogan not to cross "red lines" and has sent warships and fighter jets to the region.

Turkey in August sent an exploration ship and a small navy flotilla to conduct seismic research in waters which Greece considers its own under postwar treaties.

Greece responded by shadowing the Turkish flotilla with its own warships, and by staging naval exercises with several EU allies and the United Arab Emirates in its own show of force.

Turkey "threatens" Europe's eastern border and "undermines" regional security, Mitsotakis said Saturday.