Three European Union countries submitted a draft resolution to the U.N.'s nuclear watchdog agency Friday declaring that Iran had violated treaty obligations by secretly developing a nuclear program that could be used to build weapons. A vote on the matter by the agency's board was scheduled for Saturday, sparking complaints from countries that wanted to delay a showdown.

The resolution from Britain, France and Germany is slightly softer than an earlier version that would have immediately reported Iran to the U.N. Security Council, which could impose sanctions.

Iran, which has said it is developing nuclear technologies for electric power, not bombs, responded Friday by threatening to enrich uranium if its case goes to the Security Council.

Last month, Iran began a process known as converting uranium. Enriching uranium would be a further step toward production of nuclear fuel. Enriched uranium, depending on its quality, can be used to produce nuclear energy or nuclear bombs.

The European resolution, if approved, would declare Iran to be in "noncompliance" with its nuclear obligations, a finding that would make it obligatory for the board of the International Atomic Energy Agency to report the case to the Security Council. But the resolution leaves open the question of when a referral would be made.

A key argument that U.S. and European diplomats are using to sway Iran's backers to their side is that it would be possible to delay sending the matter to the Security Council for years if Iran changes its behavior.

While the resolution appears to have majority support on the 35-member board, it is opposed by several key members, including Russia, China and many of the board's 14 members from the Non-Aligned Movement, an international group that dates to the Cold War.

Diplomats said some of the countries opposing the resolution were threatening to stay away from Saturday's board meeting, which might deny the board the more than two-thirds quorum, or 24 members, necessary to hold a meeting. If that happened, a vote could be rescheduled, perhaps for next week.

Mohamed ElBaradei, left, head of the International Atomic Energy Agency, talks to South African and Iranian officials.