Italian Prime Minister Silvio Berlusconi told U.S. Defense Secretary Robert Gates last February that no one could stop Israel from attacking Iran if it feels an existential threat, according to a classified cable released by WikiLeaks.

The contents of the cable were published on Sunday in the German weekly Der Spiegel.

"No one, including [U.S. President Barack] Obama, can stop Israel if it feels an existential threat," Berlusconi is reported to have said.

Berlusconi concluded that Iran is secretly working to build a nuclear weapon.

He also warned that, in a preemptive strike, Israel might use nuclear weapons.

Gates told Berlusconi about an Israeli Air Force exercise in June 2008, in which IAF aircraft flew over 800 kilometers to Greece, a hint at the ability of IAF aircraft to reach Iran.