The United States has imposed the first wave of sanctions on Iran making good the promise earlier made by President Donald Trump.

In a televised speech made just hours after the US measures were reinstated on Tuesday, Iran’s President Hassan Rouhani condemned Washington for launching what he described as “psychological warfare” against the Islamic Republic, Deutsche Welle reported.

"They want to launch psychological warfare against the Iranian nation and create divisions among the people," Rouhani said.

"America will regret imposing sanctions on Iran," Rouhani said. "They are already isolated in the world. They are imposing sanctions on Iranian children, patients and the nation," he added.

© AP Photo / Susan Walsh Trump: Anyone Doing Business With Iran Won't Be Doing It With US

The economic situation in Iran has been deteriorating since President Trump said in May that the US would withdraw from the 2015 nuclear deal with Tehran and re-introduce sanctions that had been listed as part of the agreement.

As Tuesday’s deadline for the first wave of US sanctions neared, fear of their possible impact sparked a currency crisis with the rial losing two-thirds of its value since the start of the year, plunging to an incredible 109,000 to one US dollar.

Many companies, wary of the sanctions Washington had threatened to slap on foreign companies that continue working with Iran, have pulled their businesses out of the country.

The first wave of US sanctions targeting Iranian exports, the country's financial system and its ability to access the global financial system, took effect at midnight on Tuesday. A second wave of sanctions to target Iran’s energy sector is scheduled to come on November 4.

The 2015 nuclear deal, also known as the JCPOA, eased sanctions earlier imposed on Iran in exchange for Tehran curtailing its nuclear weapons program.

On May 8, President Donald Trump said he was withdrawing the US from the nuclear agreement with Tehran and promised to impose the “highest level” of sanctions on the country’s energy, petrochemical and financial sectors despite objections from Europe as well as Russia and China who have repeatedly defended the deal.

READ MORE: EU Activates Blocking Measures as US Reimposes Sanctions Targeting Iran Economy

On Monday, the foreign ministers of Germany, Britain and France issued a joint statement condemning the new US sanctions on Iran.

The European Union, for its part, has pledged to protect the interests of European companies that could suffer as a result of Washington’s sanctions.