The Israeli government, skeptical of Iran’s recent diplomatic outreach, believes that the Islamic republic has embarked on a “smile and enrich” strategy to divert attention as it seeks to rapidly expand its nuclear capability, according to an internal assessment.

The assessment, described as reflecting the judgment of the country’s senior security and policy officials, concludes that Iran will try over the coming weeks to win relief from harsh economic sanctions through a combination of diplomatic charm and “cosmetic” nuclear concessions. But it says Iran’s recent actions show no sign of willingness to make meaningful cuts in its nuclear program.

“The current Iranian charm offensive aims at reaching a deal with the international community that will preserve Iran’s ability to rapidly build a nuclear weapon at a time of its choosing — the so-called breakout option,” states the assessment, a copy of which was provided to The Washington Post.

[See the document]

The document surfaced on the eve of a much-anticipated U.N. speech by Iran’s new president, Hassan Rouhani, who was swept into office in June on a promise to end Iran’s diplomatic isolation and win relief from economic sanctions. The Obama administration has cautiously welcomed Iran’s change in tone, and White House officials said Monday that they are looking for concrete evidence of Iran’s willingness to shift its nuclear policies.

Israeli officials have been largely dismissive of Rouhani and have waged a campaign through the media and diplomatic channels to warn President Obama against easing economic pressure on the Islamic republic.

The Israeli document cites evidence that Iran has continued to “move full-steam ahead toward attaining a nuclear weapons capability” since Rouhani was elected. Monitoring by U.N. nuclear officials has confirmed an increase in the number and quality of centrifuges at Iran’s uranium-enrichment plants, as well as progress toward finishing a heavy-water nuclear reactor that could, when completed, provide Iran with a source of plutonium.

Iran contends that its nuclear facilities are intended only for peaceful uses.

The assessment notes that Rouhani used a similar “smile and enrich” strategy a decade ago when he served as nuclear negotiator.

The document then lists what it describes as “unequivocal demands” that must be part of any international nuclear deal with Iran: “Stop all nuclear enrichment,” “Dismantle the illicit underground nuclear facility near Qom and the cascades of second generation centrifuges in [Iran’s main enrichment plant near] Natanz,” “Remove all enriched material from its territory,” and “Stop the construction of the heavy water reactor in Arak.”