European leaders are rallying behind the International Criminal Court (ICC) after President Donald Trump called for countries to "immediately" resign from the organization, amid a broader push by the U.S. Administration to dismantle it.

Irish Taoiseach (Prime Minister) Micheál Martin pledged his support for the intergovernmental organization and said Ireland “strongly opposes efforts to undermine the court,” during his speech at the United Nations General Assembly in New York on Thursday.

Referencing the Hague-based court as he discussed the conflict in Ukraine, Martin said Russia must be held “accountable” for its actions. “There can be no impunity for war crimes… that is why Ireland is a steadfast supporter of the International Criminal Court,” he said, stressing that all “measures against it should be immediately withdrawn.”

Netherlands Prime Minister Rob Jetten issued a similar defense of the ICC earlier in the day. Without directly mentioning Trump or the U.S., Jetten reflected on how the court has come “under attack” and asked how can anyone “possibly be opposed to prosecuting the very worst crimes?" “I believe there can be only one response,” he continued. “To say: 'hands off' the ICC, and all those other institutions that protect the international legal order.” The remarks drew loud applause from attending delegates.

The ICC is recognized as the world’s highest criminal court. It draws its jurisdiction from the Rome Statute, a treaty that went into effect in 2002 and is ratified by 125 countries. Neither the U.S. nor Israel is a state party to the Rome Statute, and therefore they do not recognize the jurisdiction of the court.

Trump has long complained that the ICC oversteps its authority and should not claim jurisdiction over U.S. citizens. His calls against the organization culminated in a public appeal at the U.N. on Tuesday. During his 45-minute speech, Trump called “on all nations that are members of the ICC to officially resign from this rogue institution, immediately.”

He said the U.S. is “opposed to the out-of-control institution known as the ICC” and “will never allow U.S. service members or anyone else to be investigated or given show trials by an anti-American tribunal with no jurisdiction over us.” His call to action was swiftly rejected by German Foreign Minister Johann Wadephul.

"We will, of course, not be doing that," Wadephul told Germany's Deutschlandfunk radio station on Wednesday. He described the court as "an important institution” and said the issue is "one of the areas where we do indeed have to acknowledge a regrettable difference in policy from the U.S. Administration."

Similarly, European Council president Antonio Costa said the E.U. stands “firmly behind” the ICC and argued it’s “unacceptable to threaten or attack the International Criminal Court, its officials, and its staff.” At the U.N. assembly, the only nation to follow Trump’s lead appeared to be Naoero, a microstate island country formerly known as Nauru.

Naoero President David Adeang said in his speech late Tuesday that he would formally withdraw his country from the Rome Statute, citing the ICC’s “increasing irrelevance.” "Naoero joins a growing number of nations standing up for their sovereignty against the ICC’s illegitimate overreach,” said U.S. Assistant Secretary for East Asian and Pacific Affairs Michael DeSombre, after meeting with Naoero’s Deputy Foreign Minister.

Leaving the ICC is neither an immediate or clean break, experts tell TIME.

Withdrawal takes at least a year, and states remain bound to cooperate with proceedings opened before their departure, according to Sergey Vasiliev, a professor of international law at Open University Netherlands.

“The state that intends to withdraw has to file a notification of withdrawal from the statute, and it comes into effect only one year after such notification has been received by the depository of the treaty,” he says. “Those states are still obliged to provide full cooperation to the court for all the proceedings and cases that started while they were a state party and right until the moment when their withdrawal becomes effective.”

In addition to Naoero, five other states—Niger, Burkina Faso, Mali, Venezuela, and Chad—have moved to withdraw. Vasiliev calls their planned departures a “serious loss,” but says it is not “lethal to the existence of the ICC.” Hungary formally moved to withdraw from the ICC last year under former Prime Minister Viktor Orbán, but his successor, Péter Magyar, reversed the decision, signaling its renewed commitment to the organization.

A timeline of Trump’s campaign against the ICC Trump’s complaints with the ICC date back to his first term. In late 2017, the ICC requested to open an investigation into American actions overseas, looking into alleged war crimes committed by U.S. personnel in Afghanistan.

Trump pushed back and challenge the court’s authority. During his speech at the U.N. General Assembly in 2018, he claimed the ICC had “no jurisdiction, no legitimacy, and no authority” and vowed to “never surrender America’s sovereignty to an unelected, unaccountable, global bureaucracy.” “The United States has always objected to the ICC's exercise of jurisdiction over its service members,” says Vasiliev, noting this has been an ongoing point of contention.

However, “the ICC has jurisdiction over crimes committed on the state party territory, even when those crimes are committed by non-state party nationals,” he adds.

In 2020, Trump signed an Executive Order issuing sanctions in response to the ICC’s Afghanistan investigation, calling the court’s actions “illegitimate assertions of jurisdiction.” The sanctions and visa restrictions against personnel of the ICC were later revoked by former President Joe Biden in 2021.

In recent years, the Trump Administration’s arguments with the ICC have largely centered on the court’s investigation into possible Israeli war crimes in Gaza. The court issued arrest warrants for Israeli Prime Minister Benjamin Netanyahu, a Trump ally, and Israeli Defense Minister Yoav Gallant in November 2024.

New York City Mayor Zohran Mamdani had previously pledged to execute the ICC’s warrant and have Netanyahu arrested when he traveled to the city for the U.N. assembly. But in July, Mamdani conceded that his Administration had “reviewed every avenue available,” only to find they did not have the jurisdiction.

Shortly after returning to office in early 2025, Trump signed an Executive Order declaring a “national emergency” and imposing sanctions on the ICC over what he said was the court’s “illegitimate and baseless actions targeting America and our close ally Israel.”

Efforts were ramped up again in July, when U.S. Secretary of State Marco Rubio announced a “whole-of-government” effort “to systematically disable the ICC’s ability to operate, target American servicemen or officials, or otherwise threaten American sovereignty.” A month later, the State Department imposed sanctions on the ICC’s president, Judge Tomoko Akane, and Abdoulaye Seye, a Senegalese senior trial lawyer for the Office of the Prosecutor.

The ICC referred to the sanctions as "a flagrant attack against the independence of an impartial judicial institution which operates pursuant to the mandate conferred by its states parties." The sanctions targeting the ICC personnel were imposed under the 2025 Executive Order issued by Trump. On Tuesday, 38 civil society groups jointly filed an amicus curiae ("friend of the court") brief with the U.S. District Court in support of a lawsuit challenging the legality of the sanctions imposed that Executive Order.