Zohran Mamdani, the New York City mayor, doubled down on his support for the international criminal court on Wednesday, a day after calling on federal authorities to execute the court’s warrant for Benjamin Netanyahu’s arrest should he visit the city in the fall.

“I call on the federal government to join the international criminal court and to execute both this warrant as well as any warrant the international criminal court holds,” Mamdani told reporters at a press conference on Wednesday.

Those remarks came less than 24 hours after Mamdani called the Israeli prime minister a “war criminal” who is “not welcome in New York City” in a video statement posted on social media on Tuesday. The mayor admitted that he has no legal authority to direct New York police to arrest Netanyahu should he attend the United Nations general assembly in September. The mayor had previously said he was “in conversation” with city lawyers to determine whether his administration could arrest Netanyahu, as he had pledged to do during his mayoral campaign last year.

“I believe that Prime minister Netanyahu belongs in The Hague,” Mamdani told the New York Times last week, referring to the city in the Netherlands that is home to home to the court, known as the ICC, which issued an arrest warrant for Netanyahu in November 2024 over alleged war crimes in Gaza.

Neither the US nor Israel are members of the ICC, which the US government has long opposed and which Marco Rubio, the secretary of state, this month threatened to “dismantle” by pressuring other nations to abandon it.

The warrant, which the ICC issued for the arrest of Netanyahu and the former defence minister Yoav Gallant, accused them of war crimes and crimes against humanity, including “starvation as a method of warfare, and … murder, persecution, and other inhumane acts”.

Mamdani said he concluded his administration has no authority to execute the ICC arrest warrant, but shifted the burden on the Trump administration to do so. “It is clear that we do not have the independent legal authority to enforce this warrant,” he said in Tuesday’s statement. “The federal government, however, does – and I call on them to join the ICC and execute this warrant.”

Trump has already said he will do no such thing.

Netanyahu “will not be arrested” on US soil, the president said in a social media post earlier this week, adding that the Israeli prime minister is “fighting against the Islamic Republic of Iran” and “the only ones that should be arrested are the people that led Iran into this unprecedented spiral of death and destruction”.

Netanyahu had said in the past he was “not concerned” with Mamdani’s threat and his office said in a statement last week that the mayor “appears interested in diverting public attention from his follies and attacking the leader of the Jewish state and the only democracy in the Middle East”. It called the ICC a “kangaroo court”.

Other pro-Israel officials and legislators also slammed both Mamdani and the court.

“I think the mayor should stay in his lane,” Jonathan Harounoff, Israel’s former international spokesperson at the United Nations, told NY1, accusing him of “political theater”.

John Fetterman, one of the most staunchly pro-Israel Democrats in the Senate, called Mamdani a “clown” who should “sit down”.

“America’s not even part of that corrupt court,” Fetterman said in an interview with Fox News over the weekend. “That’s really not your purview.”

But at Wednesday’s press conference, Mamdani rejected suggestions that Israel’s war crimes in Gaza have nothing to do with New York City.

“This is something that has not only offended the conscience, the morals, the mere humanity of so many New Yorkers, but it has also ripped apart the lives of so many that have been affected by it as well,” he said. “I think that it is incredibly important that we ensure that we have done all of our due diligence when conducting a review.”