"We hope that what is contained in that response is a serious, substantive and constructive response to the P5 + 1 proposal," U.S. Ambassador to the United Nations Susan Rice told reporters after a meeting of the U.N. Security Council. "We will study the content carefully."
The "P5 +1" refers to the five permanent Security Council members and Germany, which have offered Iran a package of economic and political incentives in exchange for a suspension of Tehran's nuclear enrichment program.
(Reporting by Louis Charbonneau; Editing by Sandra Maler)