Sen. John Fetterman told New York City Mayor Zohran Mamdani to "sit down" after Mamdani floated arresting Israeli Prime Minister Benjamin Netanyahu during a planned visit to the United Nations, a move Fetterman called far outside the mayor's authority.
Fetterman, a Pennsylvania Democrat who has broken repeatedly with his party on Israel, appeared on Fox News's "Sunday Morning Futures" on Sunday and dismissed Mamdani's posturing in blunt terms. The senator called the International Criminal Court "corrupt," reminded viewers that the United States is not a party to it, and said the mayor of New York City has no power to act on an ICC warrant against a foreign head of state.
The exchange marks the sharpest public clash yet between two Democrats on opposite ends of their party's Israel divide, and it raises a pointed question about how far left-wing municipal leaders will go to insert themselves into foreign policy they do not control.
Mamdani made his remarks Saturday on The New York Times's "The Interview" podcast. He said he is reviewing whether his administration could arrest Netanyahu and described "an active conversation" with the city's legal department on the matter. The Hill reported that the mayor framed his interest as a legal obligation rather than a personal grudge.
Mamdani told the podcast:
"We're not talking about a personal assessment of Benjamin Netanyahu. We're talking about the International Criminal Court and the fact that they have a warrant out for this prime minister's arrest, and I think it's important to talk about the weight that that has as a charge and that also, as the mayor of New York City, I'll be following the laws of New York City."
The ICC issued an arrest warrant for Netanyahu in 2024, charging alleged war crimes and crimes against humanity in Palestine. The warrant cites "starvation as a method of warfare" and "other inhumane acts" against the Palestinian population in Gaza. The United States, however, is not a member of the ICC, and the court has no enforcement mechanism on American soil. No U.S. city has ever arrested a sitting foreign leader on an ICC warrant.
This is not the first time Mamdani has floated the idea. During his mayoral campaign last year, he told The New York Times he would order the NYPD to arrest Netanyahu. Now in office, he appears to be testing whether that campaign promise can survive contact with the city's own lawyers.
Fetterman did not hold back when host Maria Bartiromo raised the subject Sunday morning.
"Well, [he's] such a tough guy to say that kind of thing. He has no way to do that. Of course, obviously, America's not even part of that corrupt court."
Fetterman then said that if he were in Mamdani's position, he "would just sit down and focus on other... problems that they have in New York. That's really not your purview." He closed the point with a three-word message aimed directly at the mayor: "You and I know that. Sit down."
The senator's willingness to challenge a fellow Democrat on national television is consistent with a pattern that has made him an increasingly isolated figure inside his own party. A Quinnipiac poll earlier this year found that a majority of Pennsylvania voters want Fetterman out of the Democratic Party altogether.
Fetterman has not backed down. He has said publicly that he would leave the Democratic Party if it abandons Israel, a line that puts him at direct odds with the progressive wing now represented by mayors like Mamdani.
Netanyahu responded to Mamdani's remarks in an interview with WABC radio host Sid Rosenberg. The Israeli prime minister did not treat the arrest threat as a legal question. He treated it as a political one.
"He's with the terror actors. And I think the problem is that he doesn't recognize and he doesn't care that those who hate the Jews and Israel ultimately hate America."
Mamdani has accused Netanyahu and the Israeli military of committing genocide in Gaza, a charge Netanyahu has long denied. Approximately two months after the October 7, 2023, Hamas attack on Israel, Netanyahu said the Israeli military was "acting as morally as possible" in the Gaza Strip and accused Hamas itself of committing genocide.
A report released last month by independent experts commissioned by the U.N. Human Rights Council also made the claim of genocide in Gaza. Netanyahu has rejected those findings as well. Mamdani denies Netanyahu's claim that he supports Hamas.
The Gaza Health Ministry has reported that Israeli military operations in Gaza since the 2023 Hamas attack have killed more than 73,000 Palestinians, including more than 1,000 since both sides reached a ceasefire in October 2025. The ministry's figures do not distinguish between combatants and civilians.
Fetterman's core point, that Mamdani lacks the legal authority to arrest a foreign head of state visiting the United Nations, reflects a basic structural reality. Foreign affairs and diplomatic immunity fall under federal jurisdiction. The United States is not an ICC member state and has never recognized the court's authority to compel arrests on American soil. No New York City statute overrides that framework.
Mamdani's claim that he would be "following the laws of New York City" left unanswered which specific city laws he believes would authorize such an arrest. His legal department has not publicly disclosed any findings or recommendations. The gap between the mayor's public rhetoric and any actual legal authority remains wide.
Fetterman, meanwhile, has continued to move further from the progressive consensus on Israel. He has drawn a red line on the issue, and his willingness to appear on Fox News to criticize a Democratic mayor signals that the line is not rhetorical.
His political realignment has extended beyond Israel. Fetterman and Republican Sen. Dave McCormick filed a joint fundraising PAC as his support among Pennsylvania Democrats has eroded, a move that would have been unthinkable for most Senate Democrats a few years ago.
And Fetterman has not limited his criticism to foreign policy. He has publicly criticized his party's leftward drift after socialist candidates swept a round of Democratic primaries, warning that the direction was politically and substantively reckless.
Several basic questions remain unresolved. Mamdani has not identified which New York City laws he believes would authorize the arrest of a sitting foreign head of state. He has not said what his legal department has actually advised. He has not explained how a city police department would execute an arrest that the federal government has not sanctioned and that no American court has ordered.
The specific date of Netanyahu's planned visit to the U.N. General Assembly has not been disclosed. Whether the federal government has taken a formal position on a city mayor's authority to act on an ICC warrant is also unclear from available reporting.
What is clear is the political incentive. Mamdani ran for mayor on a promise to arrest Netanyahu. Now he is signaling to his progressive base that the promise still stands, even if the legal foundation beneath it does not.
When a big-city mayor starts consulting lawyers about arresting a foreign head of state on behalf of a court his own country does not recognize, the problem is not legal complexity. The problem is a politician who would rather grandstand on the world stage than govern the city that elected him.
