Greek Prime Minister Kyriakos Mitsotakis on Saturday announced a "robust" arms purchase program 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 program that will become a national shield," the prime minister said in a keynote address in the northern city of Thessaloniki.

Mitsotakis said Greece would acquire 18 French-made Rafale warplanes in addition to four multi-purpose frigates and four navy helicopters whilst also hiring 15,000 new troops and pouring resources into the national arms industry and cyber-attack defense.

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

Turkey in August sent an exploration ship and a small navy flotilla to conduct seismic research in disputed Mediterranean waters west of Cyprus, an operation that Greece condemned as illegal. Ankara and Athens both view the area as part of their continental shelf.

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 (UAE) in its own show of force.

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

Athens has disputed Ankara's current energy exploration activities in the Eastern Mediterranean, trying to box in Turkish maritime territory based on small islands near the country's enormous coastline, the longest in the Eastern Mediterranean.

Ankara has sent out drillships to explore for energy on what it believes to be its continental shelf, saying that Turkey and the Turkish Republic of Northern Cyprus (TRNC) have rights in the region.

Dialogue for fairly sharing these resources will be a win-win for all sides, Turkish officials have said.