Shimon Peres, the Israeli president, had earlier delivered a similar message to delegates, in an apparent move by Israel to soften its new government's hawkish image.
Both Netanyahu and Peres stressed that Iran must not be allowed to develop nuclear weapons, which Israel, the US and others say is the aim of Tehran's nuclear programme.
Tehran denies the allegations and says its nuclear programme is for purely civilian purposes.
"For the first time in my lifetime, Arabs and Jews see a common danger," Netanyahu said, referring to Iran.
"There is a great challenge afoot. But that challenge also presents great opportunities."