U.S. President Donald Trump made the announcement on Truth Social on Thursday, shortly before meeting Chinese President Xi Jinping in South Korea at the Asia-Pacific Economic Cooperation (APEC) summit.

He instructed the Pentagon to resume nuclear testing immediately, stating that the U.S. nuclear arsenal would reach parity with Russia and China within five years and that this step was necessary to compete on an “equal footing” with other powers.

“No One Is Above International Law”

Iranian Foreign Minister Abbas Araghchi called Trump a “nuclear-armed bully who renamed the Defense Department the ‘Department of War’” in a late Thursday post on X. He described the U.S. move as both “regressive” and irresponsible, criticizing Washington for demonizing Iran’s peaceful nuclear program.

Araghchi also condemned U.S. threats against Iran’s secure nuclear facilities, calling them a clear violation of international law.

Global Nuclear Race and Reactions

Experts note that Trump’s decision is more a response to recent nuclear developments by Russia and China than to ongoing disputes with Iran over its nuclear program. Ankit Panda, senior fellow at the Carnegie International Peace Foundation, told Al Jazeera that Washington’s move reflects global power dynamics.

Russia, following tests of its Burevestnik nuclear-powered cruise missiles earlier this month, announced tests of its Poseidon nuclear-powered supertorpedo this week. China recently showcased its nuclear capabilities during a September military parade, displaying new and modified systems including the Dongfeng-5 intercontinental ballistic missile.