Six world powers, including China, agreed on Wednesday to start drawing up new sanctions on Iran over its nuclear program in the next few days, a source with knowledge of the talks said.
The source said representatives of Britain, the United States, France, Russia and Germany had reached agreement with Beijing during a conference call.
"It has been agreed with China to start drawing up sanctions on Iran," the source said. "Drawing up of a Security Council resolution is to begin in the next few days."
"This is a big victory for the United States and the Europeans," said the source. "China has taken great strides."
Meanwhile, the White House expressed confidence that the US can work with China to move forward on bringing tougher sanctions on Iran.
"The Chinese know that it's not in their interest to have a nuclear arms race in the Middle East and we're confident that we're going to be able to work with them to move forward on (bringing) meaningful pressure on Iran," said White House spokesman Bill Burton.
Diplomats say China has been slowly and reluctantly falling in line with the other powers involved in the negotiations on Iran by backing the idea of new UN sanctions against Tehran but Beijing wants any new steps to be weak.
They say the four Western powers would like a resolution to be adopted next month, before a month-long UN conference on the nuclear Non-Proliferation Treaty in May, but acknowledge that negotiations will probably drag on at least until June.