A senior European diplomat familiar with the issue said there was general agreement among the five permanent Security Council members that ¡ª if Iran remains defiant beyond March 6 ¡ª the council would slowly increase pressure.

A first step could be a council declaration urging Iran to comply with the resolution, the diplomat said on condition of anonymity because the strategy was confidential.

Agreement on the final wording of the text was achieved overnight, only after Washington compromised on a dispute with Egypt over linking fears about Tehran's atomic program to a Middle East zone free of weapons of mass destruction ¡ª an indirect reference to Israel.

The final resolution recognized "that a solution to the Iranian issue would contribute to global nonproliferation efforts and ... the objective of a Middle East free of weapons of mass destruction, including their means of delivery."

Israel, which is not an IAEA board member, welcomed Iran's referral and the call for a nuclear-free Middle East. Experts say Israel has the world's sixth-largest stockpile of nuclear weapons, but the Jewish state neither acknowledges nor denies having such a program.