Meir Dagan, the head of Mossad - Israel's top spy agency - says Iran will have a nuclear weapon within three years.
That assessment runs counter to a report from America's intelligence community last year. The report said Iran has not worked on making nuclear weapons since 2003.
But the Jerusalem Post reports the Israeli government disagrees and says Iran has since restarted its nuclear program.
It says Iran will continue to give rockets to the Palestinians and other armed groups in the region.
"Rockets and missiles are a more substantial threat than they were in the past," the Jerusalem Post quoted Dagan. "Syria is upgrading its arsenal of surface to surface missiles, and the number of missiles and rockets it possesses today is twice the amount it had only two years ago."
Because of Tehran's continued nuclear ambitions and because of its support of more looming threats - such as Hamas, Hezbollah and Syria - Iran remains the chief strategic threat to Israel, according to the report.
Dagan says the U.S. intelligence report has now made it more difficult to impose sanctions on Iran and put a stop to Iran's nuclear program, thus "leaving Israel to face the threat alone.
Source: The Jerusalem Post