New York City Mayor Zohran Mamdani denounced U.S. military strikes against Iran on Saturday, a statement that tests his increasingly cooperative relationship with President Donald Trump.

"The military action launched today by the United States and Israel is a catastrophic escalation of illegal and aggressive warfare," Mamdani stated during an unrelated event in Brooklyn on Saturday. "Bombing cities, killing civilians, opening new fronts—the American people do not want this. The American people do not want another war for regime change. We want solutions to the cost-of-living crisis, we want peace."

Mamdani's condemnation of Trump's military action comes shortly after the two met at the White House on Thursday. Following that meeting, Mamdani told reporters they had a "productive" discussion about housing development in New York City and that he looked forward to continued cooperation with the president.

The rapid shift from a friendly tone during their meeting to Saturday's strong rebuke highlights the delicate balance Mamdani is attempting: cooperating with the president while avoiding being too closely associated with a figure deeply unpopular with his own political base.

Any criticism of Trump by Mamdani risks angering the unpredictable president. Trump has so far refrained from implementing the large-scale deployments of ICE agents and federal funding cuts to New York City that he has applied to other blue cities. Meanwhile, Mamdani's questioning last month of the legality of the Trump administration's attempt to capture Venezuelan leader Nicolás Maduro did not provoke a strong reaction from the president.

"My relationship with the president has always been candid and direct. We clearly express policy disagreements, both publicly and privately. Given the scale of the consequences we are discussing, I believe it is crucial to speak out publicly on this," Mamdani said.

During Mamdani's campaign for mayor, Trump leveled some of his sharpest attacks against him, largely due to Mamdani's foreign policy stance. Mamdani had previously stated that he would seek the arrest of Israeli leader Benjamin Netanyahu if he set foot in New York.

Mamdani issued his statement on Saturday, more than nine hours after Trump released a video statement in the early morning announcing a "major military operation" inside Iran.

Trump made clear that the objective of the military action was regime change, stating that after the bombing concludes, the Iranian people should "take over" the country from the hardline clerics who have ruled with an iron fist for decades.

Iranian media reported that the strikes killed dozens of female school students. Other reports indicated that Iran's Supreme Leader Ali Khamenei was also a target, with plumes of smoke seen rising from his compound in the capital, Tehran. Khamenei's condition remains unknown.

Before Mamdani's statement, the New York Police Department was among the first to respond to the major development, issuing a statement early Saturday morning that it was "increasing patrols at sensitive locations citywide, including diplomatic, cultural, religious, and other related sites" in light of the U.S. military action.

"Out of an abundance of caution, we are enhancing inter-agency coordination and increasing patrols at sensitive locations," Mamdani said on Saturday afternoon.

The mayor also addressed New Yorkers of Iranian descent: "You are part of this city—you are our neighbors, small business owners, students, artists, workers, and community leaders. You are safe here."