New York City Mayor Zohran Mamdani, who previously pledged to arrest Benjamin Netanyahu if he visited the city, now says he does not have the "authority" to do so.

In a video posted on social media, Mamdani instead called on US officials to act on the International Criminal Court's arrest warrant for the Israeli Prime Minister over alleged war crimes.

Technically, if Netanyahu set foot in an ICC member state, he could be arrested and handed over to the court - but the US is not a member of the ICC.

President Donald Trump has said Netanyahu would not be "arrested, in any way, shape or form" while in the US.

"He is fighting against the Islamic Republic of Iran, which recently killed 52,000 innocent protestors [sic], and has spent the last 47 years killing American Soldiers, and others," Trump said in a Truth Social post on Monday.

Trump was responding to comments Mamdani made in an interview with the New York Times on Saturday, in which the mayor said he was having "an active conversation" with law enforcement about the possibility of enforcing the ICC arrest warrant.

But on Tuesday, Mamdani said his team had reviewed "every avenue available" under the law, and concluded that "we do not have the independent legal authority to enforce this".

"The federal government, however, does," Mamdani stated. "And I call on them to join the ICC and execute this warrant."

Mamdani said in the social media video that Netanyahu was "not welcome" in New York City, where he is expected to travel in September for the UN General Assembly.

The ICC issued an arrest warrant for Netanyahu in 2024 over alleged war crimes in Gaza, while also issuing an arrest warrant for a Hamas commander.

The ICC has the authority to prosecute those accused of genocide, crimes against humanity and war crimes on the territory of states party to the Rome Statute, its founding treaty.

During his campaign for New York City mayor, Mamdani repeatedly called Netanyahu a war criminal, and the war in Gaza a genocide.

He also said he would order police to arrest Netanyahu if he arrived in the city.

Speaking then to the New York Times as a candidate, he said: "This is something that I intend to fulfill." He said that such an arrest would be honouring a warrant issued by the ICC.

His remarks come as Democratic voters' support for Israel appears to be shifting, with a recent poll suggesting 58% of Democrats believe the US is too supportive of Israel, up from 45% in 2024.

In response to Mamdani's interview, Danny Danon, the Israeli ambassador to the UN said to the mayor: "You were elected to serve New Yorkers, not Hamas' propaganda."