Much of the damage was done when US President Donald Trump's aggressive rhetoric spooked investors and triggered a run on the rial.
The currency plunge and soaring inflation have sparked sporadic demonstrations against profiteering and corruption, with many protesters chanting anti-government slogans.
The US military confirmed it has seen an increase in Iranian activity, including in the Strait of Hormuz, a strategic waterway for oil shipments that Iran's Revolutionary Guards have threatened to block.
Rouhani’s political standing has become more precarious over the unravelling of the nuclear accord he championed.
The dollar was being offered for as much as 87,000 rials.
The government will sell the US dollar at a rate of 42,000 rials to all individuals and businesses.