Greece has signed a $1.5 billion agreement with Lockheed Martin for a major upgrade of its F-16 fighter fleet over the next seven years.

The Greek defence minister, Nikos Panagiotopoulos, told parliament earlier this month that the country’s 84 F-16s would be uprgraded to the more technologically advanced Viper Class.

Mr Panagiotopoulos said the speed of the upgrade would depend on the number of the aircraft that would be needed to be in active service during the upgrade.

The deal had been approved by the US State Department in 2017.

READ MORE: Greece can talk Turkey but not under a cloud of threats, says Mitsotakis

Greece has faced defence spending cuts during the financial crisis years between 2010 and 2018.

Tensions with Turkey have escalated in the last months of the year with Turkish oil exploration vessels being sent to the northern coast of Cyprus and most recently, when Turkey signed of an exclusive economic zone with the Libyan government in Tripoli.

In October, US Secretary of State Mike Pompeo came to Athens to sign a revised defence cooperation pact which extended US military activities at three Greek bases and increasing operations at the Souda Bay US Navy base in Crete.

The agreement has been presented to the Greek parliament for ratification this week.

At the same time, there has been an increase in the number of violations of Greek air space by Turkish aircraft.

Greek authorities reported that yesterday alone there had been 20 overflights by Turkish F-16 and F-4 fighters that began at 11am and continued throughout the day. Similar breaches of airspace took place on Christmas and Christmas Day. Prime Minister Kyriakos Mitsotakis went to the Greek island of Kasos on Christmas day to highlight the breaches of Greek airspace.

The Hellenic National Defence General Staff said the Turkish aircraft were intercepted by Greek jets in line with the international rules of engagement.

Meanwhile, greekreporter.com states that Greek military authorities have issued a report highlighting a dramatic increase of Turkish violations of Greece’s territorial waters in 2019.

The Greek Defence General Staff (GEETHA) said in a report that in 2019 Turkish navy and coast guard vessels violated Greek waters 2,032 times. By comparison there were 1,479 violations of Greek territorial waters in 2018.

The GEETHA report would be used by the Greek Ministry of Foreign Affairs to determine the appropriate diplomatic response to the breeches of international law.