JERUSALEM, Dec. 4  Israel today took a darker view of Iran’s nuclear ambitions than the assessment released by United States intelligence agencies yesterday, saying it was convinced that Iran was pursuing nuclear weapons.

It said Iran had probably resumed the nuclear weapons program the American report said was stopped in the fall of 2003. “It is apparently true that in 2003 Iran stopped pursuing its military nuclear program for a certain period of time,” Defense Minister Ehud Barak told Israeli Army Radio. “But in our estimation, since then it is apparently continuing with its program to produce a nuclear weapon.”

Israel led the reaction around the world today to the new intelligence assessment released in the United States on Monday that Iran had halted its nuclear weapons program in 2003.

Iran welcomed the report. “It is natural that we welcome it,” the Iranian foreign minister, Manouchehr Mottaki, told state-run radio. “Some of the same countries which had questions or ambiguities about our nuclear program are changing their views realistically.”