Clinton told Senators she had spoken with Russian Foreign Minister, Sergei Lavrov, about the draft resolution. Moscow had said earlier it shared U.S. concerns about the Tehran accord.

Among the permanent Security Council member states, China has been the most reluctant to support new Iran sanctions, but U.S. officials have said China has been a full participant in U.N. sanctions negotiations.

Secretary Clinton attends a U.S.-China strategic and economic dialogue in Beijing next week.