Iran was holding a military exercise and testing rockets on Saturday, a day after the United States imposed fresh sanctions on Tehran in response to a ballistic missile test last weekend.
Iran's Revolutionary Guard emphasized that the military exercise was a response to "threats and sanctions" by Washington.
On Friday, the US Treasury Department added 13 individuals and 12 companies to its sanctions list for their role in Iran's ballistic missile programme as well as for providing support to the Corps-Qods Force of the Revolutionary Guard.
Iran criticized the move, saying it would not allow its domestic security to become the focus of international debate.
"The amateur and irrational policies of the new US administration will change nothing about the principles of Iranian politics," the Iranian Foreign Ministry said in a statement.
Earlier in the week, US National Security Advisor Michael Flynn said the missile test was a violation of UN Security Council Resolution 2231, which prohibits Iran from participating in any activity related to ballistic missiles designed to be capable of delivering a nuclear weapon.
Iran maintains the missile cannot carry a nuclear warhead and the test was not in violation of the UN resolution.
On Saturday, US Defence Secretary James Mattis called Iran "the single biggest state sponsor of terrorism in the world."
At a joint press conference with Japanese Defence Minister Tomomi Inada in Tokyo, Mattis, however, added that, "I don't see any need to increase the number of forces we have in the region at this time."
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