Israel acquired a fourth German-made submarine that can launch nuclear warheads yesterday.
Defence Minister Ehud Barak said the submarine would increase Israel's capabilities and strength "in the face of the growing regional challenges."
The Dolphin-type military submarine is one of six Israel has ordered from the German government, which subsidises the vessel's construction.
Each submarine costs half a billion pounds. The sub was presented to Israeli officials in Hamburg, Germany, yesterday and is expected to arrive in Israel in 2013 following final tests.
Israel already has three German-made Dolphin-class submarines capable of carrying nuclear-tipped missiles.
But there is no evidence they have been armed with such weapons and the country has never confirmed reports that it possesses a nuclear arsenal.
Israel accuses Iran of developing nuclear weapons and has hinted that it is ready to strike Iranian nuclear facilities to prevent Tehran from making an atomic bomb.
But Iran claims its nuclear programme is for peaceful purposes.
Talks on Tehran's nuclear programme are due to resume later this month in Bagdhad, but Israel has refused to rule out the use of force on the issue.
The Dolphin subs could be deployed to the Gulf as part of an Israeli strike on Iran.
The sale of the submarines sparked criticism from German Nobel-winning author Guenter Grass, who blasted Israel's nuclear arsenal in a recent poem.
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