Brennan’s comment came in the wake of mass protests that have been underway in Iran for nearly a week. Trump earlier backed the protesters and said "the US is watching" the situation.

Axar.az reports citing Sputnik.

Former CIA Director John Brennan has slammed President Donald Trump and his administration’s hardline stance towards Iran, including Trump’s persistent criticism of the Iranian nuclear deal.

According to Brennan, the president’s policy is undermining the chance of "peaceful political reform" in Iran.

"With the wholesale condemnation of Iran and nuclear deal over past year, the Trump Admin squandered an opportunity to bolster reformists in Tehran and the prospects for peaceful political reform in Iran. Bluster is neither a strategy nor a mechanism for the exercise of US power and influence," Brennan said in Twitter on Tuesday.

Brennan was CIA director during the presidency of Barack Obama and has been known as a critic of Trump’s foreign policy.

The final agreement on Tehran’s nuclear program (officially known as the Joint Comprehensive Plan of Action, or JCPOA) was one of the milestone diplomatic achievements under Obama, but has been repeatedly condemned by Trump, whose administration announced in October that it would not certify Iran’s compliance with the deal.

Brennan’s remark comes amid the ongoing protests across Iran against the worsening economic situation in the country. The protests, the largest since the 2009 presidential election, erupted nearly a week ago in response to a surge in fuel and food prices in the country, as well as unemployment, inflation and air pollution. At least 21 people have reportedly been killed in the unrest.
Explaining the popular unrest, President Hassan Rouhani cited domestic problems and foreign provocations.

Trump has commented on the situation several times, saying that that the protests in Iran showed citizens' disagreement with Tehran's funding of terrorism and warning that the US is "watching very closely for human rights violations."

Rouhani responded to Trump, saying the US president had no right to weigh in on Iran's unrest after he called the Iranian people "terrorists."