Iran is close to a "technological breakthrough" that would enable it to build nuclear weapons, Israel's military intelligence chief said in a rare public assessment Tuesday.

Maj. Gen. Amos Yadlin said Iran has enriched enough uranium this year at its facility in Natanz to build a bomb and is on the brink of a "technological breakthrough" that would enable it to build atomic weapons.

He noted, however, that the uranium must be further enriched if Iran wants to build a weapon. He did not say when Iran might reach full weapons capability and did not elaborate on what technology Iran is allegedly nearing.

The countdown on Iran's nuclear technology clock "has almost finished ticking," he said, speaking to a security conference at Tel Aviv University. U.N. monitors have confirmed that Iran has generated enough low-enriched uranium to build a bomb — if it were enriched up to a military grade of over 90 percent.

Yadlin rarely speaks in public, and the comments reflected Israel's concern about Iran. Israel views Iran as its most dangerous enemy due to its nuclear program and its missiles that can hit Israel. Iran insists that its nuclear program is for peaceful purposes, but the U.S. and its allies accuse it of secretly seeking to build weapons.

Israel is widely believed to have an arsenal of hundreds of nuclear weapons but has avoided confirming or denying their existence.

Israel has called for a diplomatic solution to the Iranian nuclear issue, while hinting it could use force if Iran is not prevented from building a weapon.

Speaking in Austria on Monday, Israel's defense minister, Ehud Barak, called for tougher new sanctions on Iran.

Barak suggested that military strikes should remain an option, saying Israel does not "remove any options off the table." But he insisted, "We still believe that it's time for diplomacy, tough diplomacy.

"There is a need for tough sanctions ... something that is well and coherently coordinated to include the Americans, the EU, the Chinese, the Russians, the Indians, Barak told reporters in Vienna.