Israel announced on Thursday that its joint military campaign with the United States against Iran was entering a "next phase," while Tehran signaled a defiant stance against negotiations.

U.S. and Israel launched airstrikes on Iran starting Feb. 28, killing over 900 people, including Iran's Supreme Leader Ali Khamenei and more than 165 elementary schoolgirls, according to Iranian authorities.

The war has since extended its geographical scope, risking drawing more countries into the conflict.

Tehran has retaliated with drone and missile attacks targeting Israel and U.S.-linked sites in Gulf countries, disrupting energy routes.

Despite the pressure, Iranian Foreign Minister Abbas Araghchi told NBC News on Thursday that Tehran is not seeking a cease-fire or diplomatic talks with Washington.