"The time has come to reinforce the armed forces... these initiatives constitute a robust program that will become a national shield," Greek Prime Minister Kyriakos Mitsotakis said on Saturday during an economic address in the northern city of Thessaloniki.
The weapons purchase will include 18 French Rafale fighter jets, four frigates and four navy helicopters.
Tensions have flared between Greece and Turkey over oil and gas exploration rights in the Eastern Mediterranean, prompting fears of more severe conflict.
Turkey has dispatched a seismic research vessel — and warships to escort it — to an area in the sea that is disputed with Greece. There have been encounters with rival Greek vessels.
Mitsotakis said that Greece will also strengthen its armed forces after years of "de-investment."
“The time to balance our needs and our capabilities has arrived. We must strengthen our armed forces for the safety of our country, it is our utmost duty towards the Greeks, who will bear the cost - the price of our place on the map," he said.
The country's armed forces, the premier said, will also hire 15,000 soldiers over the next five years.
The European Union - of which Greece is a member - has previously called for dialog, but has sided with Athens.
Last week, Mitsotakis said resolving the dispute with Turkey through dialog was important provided that the talks were held on peaceful terms, and not “at gunpoint.”