Vienna - Scenarios in which Iran would use its uranium enrichment programme to resume alleged weapons work are "plausible," the United States' representative to the International Atomic Energy Agency (IAEA) said Thursday in Vienna.

As Iran had a history of lack of cooperation with the IAEA, member states should worry about the possibility that the country would either one day kick out agency inspectors and use its enrichment facility to make fuel for a bomb, rather than for its nuclear reactor, Ambassador Gregory Schulte told the IAEA board.

Alternatively, it might do the same at a secret facility, he added.

According to US intelligence estimates, Iran stopped military nuclear projects in 2004, but stands ready to resume them.

Iran's defiance of Security Council resolutions calling for a suspension of enrichment had led to a deficit of confidence, Schulte said.

"That deficit is now so deep that it is difficult to fathom," he said.

In a joint statement, Britain, France and Germany said Iran's nuclear programme had made only "negative and dangerous progress," because its continuation "continues and intensifies a threat to the stability of a troubled region."

Together with the US, Russia and China, the three European countries have offered to improve business and political ties with Iran if the country halts enrichment.