International Criminal Court prosecutor Karim Khan has defended his decision to bring war crimes charges against Israel's prime minister, saying Israel has made "no real effort" to investigate the allegations themselves.

In an interview with Reuters, he stood by his decision on the arrest warrant despite the U.S. House of Representatives voting last week to impose sanctions on the ICC in protest, a move he described as "unwelcome and undesirable."

ICC judges issued arrest warrants for Israeli Prime Minister Benjamin Netanyahu, former Israeli Defense Chief Yoav Galant and Hamas leader Ibrahim al-Masri (known as Mohammed Deif) last November on charges of war crimes and crimes against humanity during the Gaza war.

Reuters said the Israeli prime minister's office did not immediately respond to a request for comment on the statements.

Israel rejects the jurisdiction of the Hague-based court and denies committing war crimes. The United States, Israel's main ally, is also not a member of the ICC, and Washington has criticized the arrest warrants against Netanyahu and Galant.

"We are here as a court of last resort... As we speak now, we have not seen any real effort by the state of Israel to take action that would satisfy the established jurisprudence, which is investigations into the same suspects for the same conduct," Khan told Reuters.

"This can change and I hope it will," he said in an interview on Thursday, a day after Israel and the Palestinian Hamas movement reached a ceasefire in Gaza.

The Israeli investigation could have led to the case being returned to Israeli courts under so-called complementary principles. He said Israel could still demonstrate its willingness to investigate, even after arrest warrants were issued.

The International Criminal Court, which has 125 member states, is the world's permanent court for prosecuting individuals for war crimes, crimes against humanity, genocide and aggression.

Khan said Israel has very good legal expertise.

But he said, "The question is, were these judges used, were these prosecutors used, were these legal tools used to properly scrutinize the allegations that we saw in the occupied Palestinian territories, in the State of Palestine? And I think the answer to that was 'no.'"

The passage of the “Anti-Illegitimate Court Act” by the US House of Representatives on January 9 confirmed the strong support for the Israeli government among President-elect Donald Trump’s Republican colleagues.

The International Criminal Court said it noted the bill with concern and warned that it could deprive victims of atrocities of justice and hope.

The first Trump administration imposed sanctions on the ICC in 2020 over its investigations into war crimes in Afghanistan, including allegations of torture by US citizens. Those sanctions were lifted under Joe Biden’s presidency.

It is noteworthy that in 2020, the credit cards and bank accounts of then-ICC prosecutor Fatou Bensouda and other staff were frozen and travel to the United States was blocked. Any further US sanctions under Trump are widely expected to be more severe and widespread.

The International Criminal Court, established in 1998, was intended to take over the work of the temporary tribunals that conducted war crimes trials based on legal principles established during the Nuremberg trials against the Nazis after World War II.

“It is of course undesirable and unwelcome that an institution that is the daughter of Nuremberg... is threatened with sanctions,” Khan said in his interview. “People should be aware of that because this court is not owned by the prosecutor or the judges. We have 125 countries.”

"It is a matter that should concern all people of conscience," he said, declining to discuss further what the sanctions might mean for the court.