President Hassan Rohani has reassured Iranians that his government will offset the economic pressure of upcoming U.S. sanctions, a day after protests fueled by concern over a sharp fall in the value of the country's currency.

In a speech broadcast live on state television on June 26, Rohani said that government revenues had not decreased in recent months, and blamed the fall in the value of the rial on "foreign media propaganda."

On June 25, protesters gathered outside parliament after swarming Tehran’s Grand Bazaar. It was the first such protest was the first since similar demonstrations were held throughout the country at the beginning of the year.

Iran's semiofficial ISNA news agency reported June 26 that many of the protesters, which it referred to as rioters, had been detained the previous day. It did not give any numbers.

The Fars news agency and other local media reported a strike was under way for a second day on June 26 in some sections of the Grand Bazaar, and demonstrators were shouting antigovernment slogans in surrounding streets.

Some reports said that many shopkeepers closed their doors in anticipation of further unrest. The reports of a strike and shop closing could not immediately be independently verified.

The United States is due to reintroduce stark economic penalties on Tehran in coming months after President Donald Trump withdrew from a landmark 2015 deal under which world powers lifted most sanctions in return for curbs on Iran's nuclear program.

The deal, which Tehran signed with the United States, Britain, France, Germany, Russia, and China, was repeatedly lambasted by Trump during the 2016 presidential campaign and after he took office.

The resumption of sanctions could see Iran's hard currency earnings from oil export drop substantially, prompting many Iranians to convert their savings in rials into hard currencies.

"Even in the worst case, I promise that the basic needs of Iranians will be provided. We have enough sugar, wheat, and cooking oil. We have enough foreign currency to inject into the market," Rohani said.

He added that the new U.S. sanctions were part of a "psychological, economic and political war," vowing to make Washington pay a high price for its actions.

Tehran is adopting new measures including banning some imports to keep rising prices under control and help the economy absorb the effects of threatened U.S. sanctions.

With reporting by Reuters and AP