Iranian political activists signed a letter addressed to high-ranking Tehran officials on Sunday, demanding them to hold direct negotiations with the US to resolve the standoff over the nuclear deal, warning them against what they called the loss of an important opportunity, according to Iranian media.

If America guaranteed it would not go back on its promises, a dialogue could be possible a way to resolve problems with the US

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The letter said that holding talks could protect Iran's national interests as well as solve some of its problems.Signatories included former Mayor of Tehran and leader of reformist faction the Construction Party, Gholamhossein Karbaschi, former Foreign Ministry spokeman Hamid Assefi, jailed regime critic Ahmed Montazeri , journalist Jamila Kadivar and others.In an interview with national paper Etemad, Karbaschi confirmed he had signed the letter, saying: "If America guaranteed it would not go back on its promises, a dialogue could be possible a way to resolve problems with the US without preconditions."Karbaschi described the letter as an "analysis" of its activist authors, adding that it does not represent the official stance of the country's decision makers.He said their arguments stem from the foreseeable problems faced by Iran when the US withdraws from the nuclear agreement, adding that Iran could benefit from the fact that US-European relations are currently in bad shape following Trump's so-called trade war with his transatlantic allies.Karbaschi also said that the current atmosphere in Iran is one of negativity amid the prospect of reinforced sanctions that may well cripple the economy and put further pressures on Iran.He added that it would be good for leaders to "open the door" to negotiations in order to maintain order, preserve the 1979 revolution, and solve the problems being experience by Iranian citizens.In December 2017, Iran witnessed a wave of protests across the country over living standards and economic conditions. As many US-affiliated companies cease doing business on Iran, on top of hefty sanctions imposed by the US, the forecast for Iran's dwindling economy is gloomy.The letter comes after US President Trump held historic talks with longtime adversary over North Korea, tentatively agreeing to lift sanctions on the communist state in return for its total denuclearisation.The Iranian government balked at the agreement, warning North Korea that Donald Trump could withdraw at any point, just as he did with the 2015 nuclear accord.Relations between Iran and the US have been frosty since Trump announced the withdrawal from the nuclear agreement, with Iran threatening to ramp up uranium enrichment if the deal falls through.Iranian President Hassan Rouhani said on Wednesday his country would not be able to remain in the 2015 nuclear accord unless it benefits from the agreement's provisions.

In a phone conversation with French President Emmanuel Macron on Tuesday, Rouhani said the Europeans must find a way to compensate Iran if they want to preserve the landmark agreement, following President Donald Trump's decision to withdraw from the deal and restore sanctions.

Co-signers France, Britain, Germany, Russia and China want to preserve the accord, which limits Iran's nuclear activities in return for lifting international sanctions.