The Israeli media speculation began late last week with reports in the mass-circulation tabloid Yediot Ahronot saying that Prime Minister Binyamin Netanyahu and Defense Minister Ehud Barak are pushing for an attack on Iran's nuclear facilities. The Israeli cabinet was said to be divided on the matter.

In a speech to lawmakers at the opening of the Knesset's winter session on Monday, Netanyahu said that a nuclear Iran would pose a grave threat to Israel, the Middle East and "the entire world."

In comments that may have been directed at Iran or Hamas-controlled Gaza - the source of an escalation in rocket attacks in recent days that killed an Israeli civilian and have disrupted life in southern Israel - Netanyahu spoke bluntly about pre-emption.

"Our policy is guided by two main principles: the first is ‘if someone comes to kill you, rise up and kill him first,' and the second is ‘if anyone harms us, his blood is on his own hands,'" he said.

"For 2,000 years our people could not realize these two basic principles of self defense. The Jewish people paid the ultimate price in the history of the world due to this inability. This changed when the State of Israel was established, and the Israel Defense Forces was founded."