AP - The head of Iran�s nuclear program said Monday the U.S. killing of a high-ranking Iranian general has weakened the fight against the Islamic State extremist group in the region.

Ali Akbar Salehi told a meeting of the International Atomic Energy Agency in Vienna that last month�s drone strike that killed Gen. Qassem Soleimani showed �the U.S. administration has not yet come to its senses in recognizing the realities on the ground.�

Washington targeted Soleimani, who headed Iran�s expeditionary Quds Force, saying that he was planning attacks on Americans. In his role, Soleimani was also critical to efforts to mobilize militias in Iraq to fight the Islamic State group, and Salehi called him �the most instrumental element in combating ISIS.�

Tehran retaliated for the killing of Soleimani by launching a barrage of missiles on on two Iraqi military bases hosting American troops. There were no fatalities. Salehi reiterated, however, that Iran was prepared to do more.

�Be it known as my country strongly retaliated once, it will never hesitate to strike back when necessary,� he said.

The U.S. last month added new sanctions on Salehi�s Atomic Energy Organization of Iran and on Salehi himself, freezing any assets the director had within U.S. jurisdiction.

In Vienna, U.S. Energy Secretary Dan Brouillette focused his remarks on Iran�s nuclear program, saying Tehran was still not providing the IAEA with answers about the discovery of uranium particles in a warehouse near the Iranian capital.

�We call on Iran to cooperate fully with IAEA in monitoring and inspecting Iran�s facilities, and in addressing all of the agency�s questions,� he said.

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