"We are in very complex and challenging days," Netanyahu told lawmakers in a brief address to parliament. "We are keeping our eyes open and are prepared for any scenario."

He also reiterated a warning to Iran's leadership: "I have conveyed to the ayatollah regime that if they make the gravest mistake in their history and attack the State of Israel, we will respond with a force they cannot even imagine."

The premier further highlighted Israel's close military cooperation with the US, as Washington continues to build up its military presence near Iran and in the Middle East.

"The alliance with the United States has never been closer," Netanyahu said.

"Between the Israel Defense Forces and the United States military, between our security agencies and their security services, there has never been anything like this," he added.

Arch-foes Israel and Iran faced each other in a first direct confrontation last June during a 12-day war in which the Israeli military targeted Tehran's nuclear facilities and ballistic missile arsenal.

Iran responded with drone and missile strikes on Israel. Later on in the war, the United States joined Israel in targeting Iran's underground nuclear facilities.