Analysts and rights groups have criticized US Defense Secretary Pete Hegseth for saying there would be “no quarter, no mercy” for Iran, warning that such rhetoric could violate international law.

Hegseth made the remarks on Friday as the United States and Israel continue military strikes against Iran, reports Al Jazeera.

Experts say threatening to give “no quarter”—meaning no mercy or acceptance of surrender—is prohibited under the Hague Conventions and other international agreements governing armed conflict. The policy is also banned under US domestic law, including the War Crimes Act of 1996.

Brian Finucane of the International Crisis Group said the comments raise concerns about whether such rhetoric could influence battlefield conduct. “It raises questions about whether this belligerent language is being translated into how the war is being fought,” he said.

The remarks came amid growing criticism of US strikes in Iran, including an attack on a girls’ school in southern Iran that reportedly killed more than 170 people, most of them children. Overall, the conflict has left at least 1,444 people dead and displaced millions.

International law prohibits executing combatants who surrender or are unable to fight, a rule reinforced during the Nuremberg Trials after World War II.

Rights groups say dismissing such legal restrictions is alarming. Sarah Yager of Human Rights Watch said language from senior officials can shape how troops behave in combat.

Meanwhile, US President Donald Trump has defended the military campaign, saying the goal is to win the war.

Analysts warn that rhetoric rejecting legal restraints could increase the risk of civilian casualties and undermine safeguards meant to limit harm during war.