Addressing the issue at a news conference, Foreign Ministry spokesman Saeed Khatibzadeh also lashed out at the "insanity" of the latest US sanctions against banks in Iran.
On Sunday the "historic defeat of the United States will be realized, and that came to be despite its attempts, trickery and extrajudicial moves," Khatibzadeh said.
"Iran again showed that the United States is not as all-powerful as it says," he added.
The embargo on the sale of arms to Iran is due to start expiring progressively from October 18 under the terms of a UN resolution that blessed the 2015 nuclear deal between the Islamic Republic and world powers.
Washington suffered a humiliating setback in August when it failed to win support from the United Nations Security Council to indefinitely extend the embargo.
President Donald Trump unilaterally withdrew the United States from the nuclear deal in 2018 before reinstating US sanctions on Iran.
Since then, the US has imposing additional sanctions on Iran as part of a campaign of "maximum pressure", with the latest on Thursday concerning 18 banks.
“They have sanctioned whatever entity that bears the title bank,” Khatibzadeh said.
"We used to say they are addicted to sanctions, but now they have reached insanity," he added.
The raft of coercive measures are sought to virtually cut off the Islamic Republic from the international financial network. Iran has denounced the sanctions as vehicles of “economic terrorism,” but has vowed that it would survive the pressure.
The spokesman added that the excessive use of sanctions had caused the Americans to "cannibalize" themselves, as well as prompted other countries to find alternatives to the US dollar.
He said Washington has worked itself into a pathological psychosis.
As an example, he reminded that Washington took the decision concerning the banks shortly after offering alleged readiness to help Tehran fight the coronavirus outbreak.
The US claims that transactions involving humanitarian goods such as food and medicine are exempt and that sanctions are "directed” at the government.
Yet statements from experts and rights groups indicate the sanctions have had dire humanitarian consequences and caused suffering for the people of Iran.
AFP and Press TV contributed to this story.