2009 at the "the earliest possible date" but added "that this is very unlikely".
Manouchehr Mottaki, the Iranian foreign minister, told state radio on Tuesday: "The condition of Iran's peaceful nuclear activities is becoming clear to the world.
"It's natural that we welcome it when those countries who in the past have questions and ambiguities about this case ... now amend their views realistically.
The report, which is the consensus view of 16 US intelligence bodies, contradicts a US assessment of Iran's nuclear programme in 2005 that said the country was determined to develop weapons despite international obligations and pressure. Weapon 'unlikely'
Monday's declassified report said Iran would be capable of producing enough enriched uranium that could be used in a nuclear weapon in
we do not know whether it currently intends to develop nuclear weapons".
The report, based on intelligence up to October 31, also found that Iran is "keeping open the option to develop nuclear weapons", but admitted "
Weeks after George Bush, the US president, warned of "world war three" or a "nuclear holocaust" if Iran got nuclear weapons, the National Intelligence Board cited "high confidence" that Tehran had halted its nuclear weapons programme in late 2003 and "moderate confidence" that it had not restarted as of mid-2007.
Iran appears "less determined to develop nuclear weapons" than the US government has been claiming for the past two years, the NIE report said, and Tehran may be more susceptible to global pressure than the US previously thought.
Al Jazeera correspondent Owen Fay said: "The assumption that Tehran has been working to develop nuclear weapons has been central to George Bush's aggressive foreign policy.
"But [the NIE] concludes just the opposite – that Iran is not close to developing a nuclear weapon.
"What's more, Bush himself was aware of the preliminary findings of this report even before he raised the spectre of another world war.
"The White House has now launched a major spin operation, trying to use this report as a tool to make the case that keeping pressure on Iran is still a strategy that works."
Harry Reid, the Democratic senate leader, has challenged Bush to completely rethink American foreign policy toward Iran in light of the report.
Continuing White House calls to put pressure on Iran, Stephen Hadley, the national security adviser, said on Monday: "The intelligence ... tells us that the risk of Iran acquiring a nuclear weapon remains a very serious problem.
"The bottom line is this: for that strategy to succeed, the international community has to turn up the pressure on Iran - with diplomatic isolation, United Nations sanctions, and with other financial pressure - and Iran has to decide it wants to negotiate a solution.
The consensus view of 16 US intelligence bodies - the National Intelligence Board.
Group chaired by by Director of National Intelligence, currently Michael McConnell.
Requested by senior civilian and military policymakers and politicians.
Normally remain classified.
2002 estimate on Iraqi weapons widely criticised as misleading.
"The estimate offers grounds for hope that the problem can be solved diplomatically - without the use of force - as the administration has been trying to do."
Britain said it favoured increasing the pressure on Iran over its nuclear programme despite the report.
Alireza Ronaghi, Al Jazeera's correspondent in Tehran, reported that Iranian officials maintain that Iran has no plans to develop nuclear weapons, an act that would be is against Islamic law and an edict issued by the Iranian supreme leader.
Two UN resolutions have been passed imposing sanctions on Iran after diplomatic wrangling among the five permanent UN Security Council members - the US, China, Russia, France and Britain - plus Germany.