A mix of anger and anguish among the Iranian public has greeted US President Donald Trump's decision to declare that Iran is not in compliance with the nuclear accord with world powers - a sharp contrast to the euphoria that followed when the deal was signed in 2015.

Iran's President Hassan Rouhani promptly responded to Trump's speech on Friday, calling it "a pile of delusional allegations" and "an insult to the Iranian people".

Just hours earlier, Trump had disavowed the nuclear deal that lifted sanctions on Iran in exchange for Iran giving up the majority of its stockpile of nuclear fuel rods. He said he wanted to impose more restrictions on Tehran's nuclear ambitions, and threatened to terminate the deal if the US Congress fails to agree to his plan.

Trump also announced that he would impose more financial sanctions on the entire Iranian Revolutionary Guard, although he stopped short of declaring it a "terrorist" organisation.

In response, Rouhani declared that his country "has not bowed down to any power, and will not do so in the future", letting slip his irritation by sprinkling his nationally televised speech with more informal Persian words.

Back to boycotts?

Rouhani's sentiment is widely shared among ordinary citizens, even among those who said that do not regularly follow politics.

"Trump is a maniac. His people don't even like him," Amir Ali, an engineering student in the city of Qazvin told Al Jazeera.

Ahmad Jafari, a native of Esfahan and an art student in Tehran, compared Trump to the former Iranian president Mahmoud Ahmadinejad, an outspoken politician who has been blamed by many Iranians for sinking the country into economic recession during his eight years in office.

"I don't like Trump and his politics," he said.

Sadra Mirsharifi, another student, said that he hopes the Europeans will not support Trump's decision.

"I think Iranians would be very angry if he wants to turn back the boycotts and sanctions," he said.

READ MORE: World leaders react to Donald Trump's speech on Iran

Mehdi Mahmoudi, an Iran-based journalist, agreed, telling Al Jazeera that Iranians "do not have any confidence in the US under the Trump presidency".

"Iran has implemented all of its commitments under the nuclear deal, but the US did not keep its promise," he said.

Under the 2015 deal signed in Vienna between Iran and six world powers - the US, Russia, Germany, France, Britain and China, as well as the EU, the leadership in Tehran scaled back the country's uranium enrichment programme. According to UN inspectors, Iran continues to be in compliance with that condition.

In exchange, sanctions on Iran's economy were lifted, and Tehran was allowed to resume trading of oil and gas in the international market. A total of $100bn in frozen Iranian assets were also released. Since then, Iran has gradually opened its country to foreign investments and welcomed more foreign visitors, injecting billions of dollars into its ailing economy.

Spontaneous celebrations erupted across the country when the Iran deal was signed in 2015, and when sanctions were lifted in January 2016, with many Iranians expressing hope of a new era of relations with the US and the West. Rouhani, who campaigned on economic and social reforms in 2013, rode on that success to win re-election in May 2017.

But since Trump took office in January, a cloud of uncertainty has returned, said Mahmoudi, the Iranian journalist.

Trump had repeatedly threatened to "tear up" the deal during the 2016 presidential campaign. In recent months, he has ramped up his rhetoric leading to the announcement on Friday.

In his speech announcing his decision, Trump said Iran's leaders "raided the wealth" of the country.

Economic bottom-line

But photojournalist Mohammad Najib said it is precisely Trump's decision that could hurt ordinary citizens, who are now "worried" about their economic future.

"We might go back to Ahmadinejad's era [recession] and sanctions," he said, adding that the country could suffer another steep currency devaluation if uncertainty persists.

That fear might not be unwarranted. Since Trump's speech blasting Iran at the UN in September, the Iranian rial has dropped from 39,000 to the US dollar to 40,600 in a matter of 16 days, according to Bloomberg. Before the Iranian presidential election in May, the exchange rate was 34,500 rial to the dollar.

In a recent article in the Lobe Blog, Esfandyar Batmanghelidj, executive editor of the digital publication Bourse and Bazaar, wrote that business leaders are also blaming Trump for the slowing of investments in Iran.

In a survey he conducted in August 2017 among 700 Iran businesses, he said that 70 percent of them believe that international investors are "moving slower than they could" to bet on the Iranian economy. Of that number, 76 percent blame "pressure or fear of the United States" as a key reason for the slowing investment situation.

Babak, a Tehran-based musician and architecture graduate, said that it is the economic bottom line that worries Iranians the most, if hostilities between Iran and the US worsen.

"All they care about is that the sanctions might come back, and life gets harder, because Iran's economy is so dependent on its relations with the US," he said.

"Some of the people are even beginning to worry about a war."

Analysts who talked to Al Jazeera, have already warned of the dangers of Trump's decision alienating regular Iranians who are most eager to have warmer relations with the US.

READ MORE: Rouhani hits back at Trump after nuclear deal speech

Adding insult to Iranians, both in the country and in the diaspora, Trump also referred to what the Iranians call the "Persian Gulf" as the "Arabian Gulf", igniting a separate firestorm on social media, and prompting Rouhani to lecture the American president to study geography and learn from his own generals.

Maziar Bahari, an Iranian Canadian journalist who was imprisoned by Iranian authorities for his reporting, posted on Twitter, "Calling Persian Gulf, 'Arabian' is the easiest way to turn every Iranian, especially those who oppose the regime, against you."

Sepideh, an art student from Sari near the Caspian Sea said, told Al Jazeera she supports whatever the government takes in response to Trump's latest decision.

Pedram Kazerooni, an illustrator and environmentalist, told Al Jazeera that many of his countrymen are against "a man who does not respond to peace, nature and human rights".

"We are not into war. We wished that Trump is a man who we could have an agreement with. But he is not that kind of person."