Washington ? Six major world powers agreed Wednesday to begin putting together proposed new sanctions on Iran over its suspect nuclear program after China dropped its opposition.

China, long a holdout against fresh international penalties against Iran, signaled its willingness to consider a U.N. Security Council sanctions resolution.

“China has agreed to sit down and begin serious negotiations here in New York … as a first step toward getting the entire U.N. Security Council on board with a tough sanctions regime against Iran,” Susan Rice, the American ambassador to the U.N., told CNN.

Secretary of State Hillary Rodham Clinton said the five permanent members of the U.N. Security Council and Germany were unified.