Iran has long pretended to defy the West, specifically the United States, and played down the importance of imposing economic sanctions on it, but the president's remarks point out the opposite.
Hassan Rowhani warned the people that he "may face difficult times" when new US sanctions come into force on Sunday, including the vital oil sector in Iran's economy.
The United States has imposed a number of sanctions on Iran after the withdrawal of Washington in May of the nuclear agreement in 2015, which aims to curb Iran's nuclear program, after Tehran's failure to comply with its provisions, as well as its interventions and subversive roles in the countries of the region.
Rohani described the sanctions move as "a new injustice" that his government is not afraid of.
"Over the past few months, our people have faced difficult times and the next few months are likely to be difficult, but the government will use all its resources to reduce these problems," he said.
The cost of living has risen in the past few months, leading to demonstrations against exploitation and corruption in Iran, during which protesters chanted slogans against the government and the regime's leader, supreme leader Ali Khamenei.
The Iranian riyal has recorded record losses against the dollar because of the threat posed by the re-imposition of US sanctions and strong demand for the dollar among Iranians trying to protect their savings.
"You will not be able to achieve any of your goals, you will not be able to completely stop or reduce oil exports," Rohani told the Americans.
Washington has said that the next package of sanctions against Tehran, aimed at a decline in Iranian oil sales to zero.
