The United States, encouraged by the signals sent by Iran’s election of Hassan Rouhani, is urging Iran to give a substantive response and negotiate seriously when nuclear talks resume in the fall, a senior US administration official said Friday, July 12.

“We have all noted Rouhani’s positive tone and remarks post-election,” the senior US administration official said in a small background conference briefing Friday. “We are glad for the positive words. But what we are looking for are actions that indicate a desire to deal seriously with the P5+1. Words are not enough. We need a concrete response.”

The American official spoke ahead of a meeting of political directors from the P5+1 — the United States, United Kingdom, France, Germany, Russia and China— in Brussels next week (July 16) to discuss preparations for a new meeting with Iran in the fall. Talks between the P5+1 and Iran are likely to resume at the earliest in September, following the inauguration next month of Rouhani, and depending on the logistics of arranging a meeting around the opening of the United Nations General Assembly in September.

The US official said the six powers are inclined to ask Iran’s new nuclear negotiating team after one is assembled under Rouhani to give a concrete response to a detailed confidence-building proposal they put forward at nuclear talks in Almaty, Kazakhstan, in February. But she stressed that it’s not a take-it-or-leave-it offer, but one open for negotiation.