"We declare to all countries... do not join the economic war waged by the United States," Mohsen Rezaei said in an interview with the state broadcaster.
"Any country participating in the imposition of economic restrictions against us is considered an enemy."
Rezaei added that "if (US President Donald Trump) wants to do something, we will retaliate in a seismic manner."
Rezaei was named this month as part of senior appointments widely seen as hardening Tehran's political and military stance. His interview with IRIB is his most extensive public statement since then.
Rezaei said Iran would target oil-shipping routes out of the Persian Gulf - alternatives to the Strait of Hormuz - if neighbours join the economic war against Iran.
Rezaei said discussions with Oman, located on the other side of the strait, over management of it were ongoing, and said fees would be imposed. Iran asserted control over what was seen as an international waterway shortly after the US and Israel attacked on February 28.
Rezaei also vowed to make changes to Iran's diplomacy and bring new capabilities to what he called the next war.
He also warned the US against sending more military personnel to the region, and said the US had increased nuclear insecurity because countries see that participating in international monitoring efforts, as Iran has done, is no protection against attack.
Earlier Iranian President Masoud Pezeshkian said the war with the US States should end since the world accepted that his country had won.
"It would be better to end the war today, when we are powerful and have dignity, and the whole world acknowledges our victory and emphasises that the United States, contrary to all regulations, attacked our schools, hospitals and infrastructure and is hated in the world," several news agencies quoted him as saying on Friday.
At an event in Tehran with the Iranian medical community, Pezeshkian defended the importance of restoring peace and fulfilling agreements.
However, he clarified that this did not mean Iran's surrender and they would not yield to intimidation in any way and give them a crushing response.
He underlined that Iranian armed forces were fully prepared to defend the country with all their might and risking their lives.
Trump said his administration would impose an "unprecedented" level of economic pressure on Iran, aiming to force its leadership to end its nuclear program and fully reopen the Strait of Hormuz to oil and natural gas tankers.
US Treasury Secretary Scott Bessent is due to hold a press conference at 2pm AEST on Monday after threatening "the toughest sanctions in history" on Iran.
Bessent has also urged co-operation with the US by China, which buys more than 80 per cent of Iran's shipped oil, according to 2025 data from analytics firm Kpler.
Iran's foreign ministry spokesman Esmaeil Baghaei said the imminent US announcement of economic sanctions was an "assertion of extraterritorial sovereignty over every independent member state of the United Nations".
"Such secondary sanctions find no foundation in international law," he said in a post on X.
with Reuters, DPA and EFE
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