A new IAEA report, released in Vienna today, says Tehran has instead expanded such activities.
The report also says that the IAEA's ability to monitor Iran's nuclear program has deteriorated because of lack of access to Iranian sites.
The report was issued after the expiration of a 60-day Security Council deadline for Iran to stop enriching uranium or face a possible third round of UN sanctions.
In Washington, the White House described the IAEA report as a list of Iran's continued defiance of the international community.
Undersecretary of State Nicholas Burns said the United States and its allies will not agree to accept even limited Iranian nuclear-enrichment activities.
Western governments say they suspect that Iran is using its civilian nuclear program as a cover to develop nuclear weapons. Iran denies this, saying it wants nuclear power to produce electricity.