Israel said on Tuesday it believed Iran had estarted its atomic weapons programme and that a US-backed campaign to curb Tehran’s nuclear ambitions must continue despite a US report it had halted the work.

“It is vital to pursue efforts to prevent Iran from developing a capability like this and we will continue doing so along with our friends the United States,” Prime Minister Ehud Olmert told reporters, adding he had discussed the new US intelligence report with Washington.

The assessment, released on Monday, said Iran’s nuclear weapons program was frozen in 2003 and remained on hold, contradicting an earlier report that the Islamic Republic was bent on building a bomb.

The report could undermine Washington’s efforts to convince other world powers to agree on a third package of UN sanctions against Iran for defying demands to halt uranium enrichment.

Israeli Defence Minister Ehud Barak said the report was incomplete and that Israel’s arch foe had probably restarted the program and that such reports were “made in an environment of uncertainty”.

“It seems Iran in 2003 halted for a certain period of time its military nuclear program but as far as we know it has probably since renewed it,” Barak told Army Radio.