Iranian officials, in their turn, argue that it is they who are reaching out.
The Iranians "want ... to show that they are the ones who are interested in cooperating, and I believe highlighting the telephone conversations and sending letter after letter is just proof that they want to show the world that they are keen on talking and the P5+1 is the one refraining," says the Iranian diplomat.
"When Bagheri wrote in his letter that if they are not getting ready for the Moscow talks they should expect failure, [this] was paving the way ... to say to the world that we did send them the message and they ... ignored it," says the Iranian diplomat.
P5+1 talks in Europe today and tomorrow
The top US negotiator in the nuclear talks, Undersecretary of State for Political Affairs Wendy Sherman, was scheduled to join other P5+1 officials for strategy talks in Strasbourg, France, today and tomorrow.
Besides the squabbling over preparations for Moscow is a more fundamental issue for Iran: the substance of the P5+1 opening bid put forward in Baghdad in late May, which Tehran says amounted to "failure."
In that proposal, Iran was asked to give up uranium enrichment to 20 percent purity – a level it has been converting into fuel plates for a research reactor, but which is technically not far from weapons-grade of 90 percent.