Iran has 'weeks' to respond

News24.com:

Iran has "weeks" to respond to a diplomatic initiative agreed on Thursday by the United States and other major powers in an effort to persuade Tehran to end its nuclear programmes, a senior US official said.

The official also said the major powers - including Britain, France, Germany, Russia and China - have agreed to take "measures with teeth" if Iran rejects the deal.

But the official, speaking to reporters on condition of anonymity, refused to spell out the measures or to call them sanctions.