Maj. Gen. Yossi Baidatz, head of research for military intelligence, warned parliament's Foreign Affairs and Defense Committee that Iran was getting steadily closer to developing a weapon.
"If nothing stops Iran, the worst-case scenario is that by the end of 2009, Iran will have a nuclear weapon," a participant in the closed session quoted Baiditz as saying.
Iran insists its nuclear program is peaceful, but its assertions are widely disbelieved. The program has especially rattled Israel because Iranian President Mahmoud Ahmadinejad has repeatedly called for the Jewish state's destruction.
Israel has mounted a diplomatic offensive to try to build international support for tougher U.N. sanctions meant to persuade Tehran to abandon its nuclear program.
Israeli officials met with all permanent members of the U.N. Security Council last month to push for new sanctions. Prime Minister Ehud Olmert made a snap trip to Moscow followed by a trip to London and Paris. Foreign Minister Tzipi Livni made the case with officials in China. Russia and China are at the forefront of resistance in the security council to slapping new sanctions on Iran.