Israeli Prime Minister Benjamin Netanyahu faced a mass walkout inside the assembly hall and large protests outside as he addressed the UN General Assembly.
Mamdani shared a video of the symbolic gesture involving families displaced from Gaza.
Zohran Mamdani said the Israeli prime minister's address repeated 'baseless lies' and pointed to the ICC arrest warrant against him.
The two leaders discussed affordable housing and immigration during a 'wide-ranging' meeting, though few details of any disagreements were shared.
The New York mayor raised the issue during a meeting with the president at his official residence, a day before Trump was set to address the UN General Assembly.
The Monday meeting, ahead of the UN General Assembly, will focus on issues affecting New York City, according to the mayor's office.
New York City Mayor Zohran Mamdani commemorated the 25th anniversary of the September 11 attacks, describing the day as the darkest in the city's history, according to Al Jazeera.
Mayor Zohran Mamdani released tens of thousands of documents ahead of the attacks' 25th anniversary, according to France 24.