It is past time for the Iranians to take the concrete steps that would reassure the world that their nuclear program is, as they claim, exclusively peaceful.
Steps it must take immediately are shutting down of the Fordow facility, freezing enrichment above five percent, and shipping all uranium enriched above five percent out of the country,
On the other hand, if the sessions in Moscow produce no substantive agreement, we urge you to reevaluate the utility of further talks at this time and instead focus on significantly increasing the pressure on the Iranian government through sanctions and making clear that a credible military option exist.
as you have rightly noted, ‘the window for diplomacy is closing.’ Iran’s leaders must realize that you mean precisely that.