Iran will ask the international community to take a position on the U.S. designation of its Revolutionary Guards as a terrorist organisation, Foreign Minister Mohammad Javad Zarif was cited as saying on Sunday.
Iran condemned U.S. President Donald Trump's step last week as illegal. The Islamic Revolutionary Guards Corps (IRGC) is a powerful elite force which controls much of the Iranian state and economy.
"Today ... we will send messages to foreign ministers of all countries to tell them it is necessary for them to express their stances, and to warn them that this unprecedented and dangerous U.S. measure has had and will have consequences," Zarif was quoted as saying by state news agency IRNA.
Zarif said he had also sent letters to United Nations Secretary-General Antonio Guterres and the United Nations Security Council to protest against "this illegal U.S. measure".
Tehran retaliated against Washington's move by designating the regional United States Central Command (CENTCOM) as a terrorist organisation.
Relations between Tehran and Washington took a turn for the worse last May when Trump pulled out of a 2015 nuclear deal between Iran and six world powers, reached before he took office, and reimposed sanctions.
The United States has already blacklisted dozens of entities and people for affiliations with the IRGC, but had not previously targeted the organisation as a whole.
Revolutionary Guards commanders have repeatedly said that U.S. bases in the Middle East and U.S. aircraft carriers in the Gulf are within range of Iranian missiles.
Tehran has also threatened to disrupt oil shipments through the Strait of Hormuz in the Gulf if the United States tries to strangle Iran's economy by halting its oil exports.
Iran's oil minister said on Sunday that the supply-demand balance in the global oil market is fragile due to U.S. sanctions on Iran and Venezuela and tensions in Libya, and warned of consequences for increasing pressures on Tehran.
France, Britain and Germany, other signatories of the nuclear accord, have set up a new mechanism for non-dollar trade with Iran to protect against U.S. sanctions.
Zarif complained on Sunday about the delay in the implementation of the mechanism, and urged Europe to make it operational as quickly as possible.
"The Europeans should not believe that the Islamic Republic of Iran will wait for long," he said.