Greece and Israel pledged Tuesday to boost defence cooperation with a view to improving regional stability, their defence ministers told reporters.

"We are committed to work together to deepen our relations in defence and security," said Israel's Ehud Barak. "We have to be prepared for many kinds of developments. ... We must think ahead of time and work together."

Traditionally pro-Arab Greece, which did not officially recognise Israel until 1991, has stepped up efforts to attract investment and expertise to shore up its debt-struck economy.

The two countries are trying to "make up for lost time", Greek Defence Minister Dimitris Avramopoulos said, asserting Greece's "commitment to deepening the alliance with Israel ... in the name of friendship, peace and stability for all the peoples of the region".

Barak's two-day visit is the fourth by a senior Israeli official in 17 months.

Israeli Prime Minister Benjamin Netanyahu visited in August 2010, followed by Foreign Minister Avigdor Lieberman in January 2011 and Deputy Foreign Minister Danny Ayalon in November, when Israel hosted a joint exercise with the Greek air force.

He said their cooperation was "honest and sincere (and) not directed against anyone", in a reference to Turkey, formerly a staunch ally of Israel but now on deteriorating terms with the Jewish state.

"To the contrary, this cooperation can create new sources of wealth for the entire region," Avramopoulos said at a time when Greece, lumbered with a severe debt crisis, hopes for economic benefits from closer ties with Israel.

Athens is keenly interested in Israel's economic rapprochement with traditional Greek ally Cyprus to develop undersea gas deposits in the eastern Mediterranean.

Pro-Palestinian Greek activists meanwhile have denounced Barak's visit, with a rights group calling him a "war criminal", and were set to stage a protest in central Athens later Tuesday.

Last July, Greece banned a flotilla of ships headed for Gaza from leaving its ports on a mission to break the Israeli blockade of the Palestinian territory.

An Israeli raid last year on another Gaza-bound aid flotilla left nine pro-Palestinian activists dead, all of them Turks or of Turkish origin, and precipitated a diplomatic crisis with Greece's regional rival Turkey.