New York mayor Zohran Mamdani has spent nearly two years vowing that Israeli Prime Minister Benjamin Netanyahu would be arrested the moment he set foot in the city. That pledge is about to be tested: Netanyahu is expected in Manhattan this September, 2026 for the UN General Assembly, and Mamdani's City Hall must now decide whether words translate into action.

A promise under review, not a guarantee

Speaking on The New York Times’ The Interview podcast last week, Mamdani said the city's Law Department was actively examining the matter, though he stopped short of promising an arrest would happen. He maintained his characterisation of Netanyahu as a war criminal responsible for the deaths of women and children in Gaza, saying the Israeli leader ought to face justice at The Hague’s International Criminal Court, which issued a warrant against Netanyahu in November 2024 over alleged war crimes and crimes against humanity, including claims that Israel used starvation as a weapon of war.

Crucially, Mamdani also drew a line around his own power, indicating that his administration would act only within existing law rather than attempt to create new legal authority to justify a detention.

Why most legal experts say it can't happen

The obstacle is straightforward: the United States is not a signatory to the ICC and does not recognise the court’s jurisdiction. Washington has gone further than mere non-recognition – President Trump imposed sanctions on the court earlier this year, rejecting any claim of authority over the US or Israel. That leaves the NYPD with no legal mechanism to enforce a warrant that the federal government has explicitly repudiated.

The US Secretary of State recently announced his campaign to “dismantle” the ICC and pressure other countries to support its stance. There’s also the matter of diplomatic protections. Foreign leaders attending UN functions in New York typically travel under the UN Headquarters Agreement, a federal arrangement that guarantees member-state representatives entry into the US for UN-related business – an area entirely outside municipal control.

US ambassador to the UN, Mike Waltz, brushed off Mamdani's renewed comments as political theatre, arguing federal authority would override anything the city attempted. The scepticism isn't confined to Mamdani's critics. Manhattan congressman Jerrold Nadler, a fellow Democrat, has long dismissed the pledge as unworkable, noting the city simply lacks jurisdiction.

Even some allies within Mamdani's progressive base – including Murad Awawdeh of the New York Immigration Coalition – have signalled that pursuing Netanyahu's arrest isn't a priority for them.

From campaign certainty to mayoral caution

Mamdani's tone has noticeably shifted since taking office. During his campaign, he spoke with conviction about following through, telling The Times in 2025 that fulfilling the pledge was something he fully intended to do. As mayor, that certainty has given way to a more measured stance: the issue is now framed as pending legal review, contingent on what city lawyers determine is actually permissible.

Political theatre or principled stand?

Former mayor Eric Adams has been among the loudest critics, calling Mamdani's rhetoric unrealistic and warning it could expose Americans working overseas to retaliatory risk. Adams said he would personally extend a welcome to Netanyahu in New York. For his part, Netanyahu has dismissed the threat outright, telling radio host Sid Rosenberg that he believes Mamdani harbours anti-American sentiment and sympathises with extremist actors – a claim Mamdani rejects.

By neither abandoning the pledge nor formally asserting a power virtually no legal analysis supports, Mamdani keeps the question technically alive. Whether or not Netanyahu is ever detained on New York soil, the pledge has kept scrutiny of Israel's conduct in Gaza in the national conversation – a debate Mamdani has consistently sought to sustain since his time as a state assemblyman.