Greece, Israel and Cyprus will step up joint air and naval exercises in the eastern Mediterranean in 2026, deepening their defence cooperation, Greek military officials and a senior source said on Monday.

The three eastern Mediterranean nations have drawn closer over the past decade through joint military drills, defence procurement and energy cooperation, developments closely watched by regional rival Türkiye.

Greece’s armed forces general staff (GEETHA) said senior military officials from the three countries signed a joint action plan for defence cooperation last week in Cyprus. It gave no further details.

The deal follows a meeting in Jerusalem between Greek Prime Minister Kyriakos Mitsotakis, Cypriot President Nikos Christodoulides and Israeli Prime Minister Benjamin Netanyahu at which they signed a deal to strengthen maritime security cooperation and advance energy interconnection projects.

A senior Greek official familiar with the matter said the military deal would encompass joint naval and air exercises and the transfer of know-how from Israel to Greece and Cyprus to address both “asymmetrical” and “symmetrical” threats.

“Greece and Israel will intensify joint exercises after the ceasefire in Gaza, with Cyprus participating,” the official said, adding that Greece plans to join Israel’s Noble Dina naval exercise in the coming months in the eastern Mediterranean.

There was no immediate comment from the Cypriot government, but a key opposition party, the Communist AKEL, expressed misgivings. “Mr Christodoulides proceeds to deepen military-political cooperation with Israel without considering the risks and consequences of this choice,” it said in a statement.

Greece and Cyprus have already purchased missile systems from Israel worth billions of euros. Athens is also in talks to buy from Israel medium- and long-range anti-aircraft and anti-ballistic missile systems for a planned multi-layer air and drone defence system known as the “Achilles Shield”, estimated to cost about 3 billion euros ($3.5 billion).

This month, the Greek parliament approved the purchase of 36 PULS rocket artillery systems from Israel to bolster defences along Greece’s northeastern border with Türkiye and on Greek islands in the Aegean Sea.