Details of the cable, from the whistle-blowing Web site WikiLeaks, were first published Sunday by Norway's Aftenposten newspaper.
The cable summed up a meeting in Israel led by U.S. Congressman Ike Skelton with members of the Israeli intelligence echelon, Israel Radio said Monday.
The chief of staff, Lt.Gen. Gabi Ashkenazi, told the visiting American delegation he was preparing Israel for war because of military buildups in the Gaza Strip and Lebanon, The Jerusalem Post said.
"I am preparing the Israeli army for a large-scale war since it is easier to scale down to a smaller operation than to do the opposite," Ynetnews.com quoted Ashkenazi saying.
An unnamed official of the Mossad, Israel's intelligence agency, estimated Hezbollah has 40,000 rockets in its arsenal and has the capacity to shoot up to 600 missiles a day at Israel in any future conflict, the Israeli daily said.
Hezbollah also has a number of Iranian Ababil unmanned aerial vehicles that can be loaded with explosives and sent to bomb strategic sites in Israel, the report said.
Israel will have up to 12 minutes to prepare its radar systems in the event of an Iranian missile attack on the country, Ashkenazi said. He said the Islamic Republic has in its possession more than 300 missiles capable of hitting Israel.
Israeli security and Army officials participated in discussions with the American delegation, the report said.