U.S. Defense Secretary James Mattis on Saturday called Iran the "world's biggest state sponsor of terrorism," reiterating National Security Advisor Michael T. Flynn comments on Tehran's alleged support for violent activities aimed at destabilizing the Middle East. Mattis' remarks come a day after President Donald Trump imposed fresh sanctions on Tehran in response to its ballistic missile test late last month.

Mattis’ comments were made during a press conference in Tokyo where he also said that as things stand now, there is no plan to increase the number of U.S. forces in the Middle East to counter the growth in Iran’s weapons capabilities. On Jan. 27, Iran test fired a ballistic missile capable of traveling 2,500 miles and of carrying a nuclear warhead.

"As far as Iran goes, this is the single biggest state sponsor of terrorism in the world," Mattis reportedly said. "It does no good to ignore it. It does no good to dismiss it and at the same time I don't see any need to increase the number of forces we have in the Middle East at this time.”

The fresh sanctions imposed on Iran target 13 individuals and 12 companies, including groups in China, Lebanon and the United Arab Emirates working to help Tehran obtain technology and materials required to advance its ballistic missile program. While announcing the sanctions, the Trump administration said that Washington would no longer overlook Tehran’s hostile actions.

"The Trump Administration will no longer tolerate Iran’s provocations that threaten our interests," Flynn said in a statement. "The days of turning a blind eye to Iran’s hostile and belligerent actions toward the United States and the world community are over."

Iran "was playing with fire" by testing medium-range ballistic missiles, Trump said in a tweet Friday. However, Tehran insisted that the missile test was meant for defensive purposes and did not violate the nuclear agreement.

However, Iran could still face tough consequences if it does not curb its ballistic missile program and continued to intervene in regional proxy conflicts, a senior U.S. administration official said, according to Reuters, adding that the latest sanctions were the initial steps in response to Iran's "provocative behavior."

On Saturday, Iran announced that it will take “reciprocal action” against U.S. individuals and companies. The country said it will deploy missiles and carry out maneuvers aimed at demonstrating its “complete preparedness to deal with the threats” and “humiliating sanctions” from Washington.

“In response to the new move by the United States of America and as a reciprocal action, (Iran) will impose legal limitations for some American individuals and companies that have had a role in the creation and support of extreme terrorist groups in the region,” the foreign ministry said. “The names of these individuals and companies will be announced later.”

The statement also added: “Missile development and capabilities of the country, which is merely designed for defensive objectives and carrying conventional weapons and that will never be used except for legitimate defence, is the right of the people of Iran based on international law and the UN charter.”