Iran on Monday vowed a "crushing" response if the U.S. designated its Revolutionary Guards Corps (IRGC) as a terrorist group.
"We are hopeful that the United States does not make this strategic mistake," foreign ministry spokesman Bahram Qasemi told a press conference cited by Iran's official IRNA news agency.
"If they do, Iran's reaction would be firm, decisive and crushing and the United States should bear all its consequences," he said.
The threat comes as the administration of President Donald Trump plans to announce its decision on the 2015 nuclear deal between Iran and the major six world powers. Trump is expected to decertify the deal.
Trump is also expected to designate the IRGC as a terrorist organization as part of his policy on the Islamic Republic.
On Sunday, the IRGC warned Washington against designating it as a terrorist group.
"If media speculations on a foolish [decision] by the US administration to designate the Guards as a terrorist organization are correct, the Guards would treat the U.S. army similar to [the way it treats] Daesh in the world, particularly in the Middle East," said Brigadier General Mohammad-Ali Jafari, the Guards' senior commander.
