G8 leaders are expected to discuss Tehran’s response, made last week but not yet disclosed publicly, to a plan from six world powers offering Iran technology and negotiations if it suspends uranium enrichment.

In an interview with German daily, Frankfurter Allgemeine, Frank-Walter Steinmeier, Germany’s foreign minister, said: If there is no progress with the Iranian regime in nuclear negotiations, we have to think of a new round of negotiations in the United Nations.