Iran could build a nuclear bomb in less than three years, the head of Israel's Mossad intelligence agency has warned.
Deputy PM Shimon Peres echoed Mr Dagan's concerns over Iran
Speaking to MPs in Israel's parliament, the Knesset, Meir Dagan said Iran's nuclear programme was nearing the "point of no return".
If Iran successfully enriched uranium in 2005 it could have a nuclear weapon two years later, Mr Dagan said.
Iran says that it is developing a civilian nuclear energy programme, but the US and Israel reject this.
They maintain the Islamic state is using the energy programme as a front for a covert weapons programme.
Last week US Vice-President Dick Cheney said Iran's nuclear programme put it "top of the list" of global issues.
Mr Dagan told the Knesset foreign affairs and defence committee that Iran is negotiating with European mediators to be allowed to continue developing uranium enrichment capability.
Iran agreed in November to halt uranium enrichment under pressure from the US, Europe and the International Atomic Energy Agency.
If it resumes enrichment and succeeds before the end of 2005, Mr Dagan said, "the route to building a bomb is a short one".
"The moment you have the technology for enrichment, you are home free," he said.
Mr Dagan said it could take Iran just two more years to develop a bomb once they had completed enrichment.
"It is up to the international community to increase its efforts to prevent the arming of Tehran."
Iran gave no immediate reaction to Mr Dagan's claims.
The Mossad chief's concerns were echoed by Israeli Deputy Prime Minister Shimon Peres.
"Iran has become the focal point of all the dangers of the Middle East," Mr Peres told Israel's Army Radio.
"This problem should be of concern to the whole world and not just Israel."
Mr Peres, widely regarded as the father of Israel's secretive nuclear deterrent, dampened suggestions that Israel was planning pre-emptive strikes against Iran, as hinted by Mr Cheney.
"The party that will decide is the United States," Mr Peres said.
"If we go it alone, we will remain alone. Everyone knows our potential but we also have to know our limits.
"As long as there is a possibility that the world will organise to fight against Iran's nuclear option, let the world organise."