THE HAGUE/BERLIN/LONDON (Reuters) - International Criminal Court Prosecutor Karim Khan's request for an arrest warrant against Israeli Prime Minister Benjamin Netanyahu has created a diplomatic quandary for some key member states: How to be supportive of both Israel and the ICC?

Khan's move on Monday, the first attempt to go after a sitting, Western-backed head of state, has yet to be reviewed by ICC judges who can amend, reject or approve it. But his step into the globally divisive Israeli-Palestinian conflict has some of the ICC's vocal backers questioning the extent of their loyalty.

Prosecutors had flagged plans ahead of time to some capitals, including Paris, London and Berlin, enabling governments to coordinate reactions. Still, many declined to say what they will do in the event that warrants over the war in Gaza are issued against Israeli leaders.

"...Of course it puts us into trouble for various reasons," a German government official said on condition of anonymity, citing Berlin's simultaneous unwavering political commitment to Israel's security and support for an independent ICC prosecutor.

Germany has already defended its policy of supplying arms to Israel at another international court in The Hague, and an ICC warrant for Netanyahu would add more unwelcome political pressure, diplomatic sources said.

It could also undermine German efforts to bolster support for the ICC in Washington, one government source said.

U.S. President Joe Biden called Khan's targeting of Israeli officials "outrageous" and said there is no equivalence between Hamas and Israel, and Secretary of State Antony Blinken said the Biden administration is willing to work with Congress to potentially impose sanctions on ICC officials.

The war in Gaza erupted after Hamas-led militants stormed into southern Israel on Oct. 7, killing 1,200 people and seizing over 250 hostages according to Israeli tallies. Over 35,000 Palestinians have since been killed in an Israeli invasion and bombardments of Gaza, with at least 10,000 more missing and much of the enclave pounded into rubble, Gaza's health ministry says.

Khan requested arrest warrants against Netanyahu, Israeli Defence Minister Yoav Gallant as well as three Hamas leaders for alleged war crimes and crimes against humanity in the conflict.

BRITAIN AND ITALY AT ODDS WITH FRANCE

Divisions in Europe over Khan's decision reflect a deeper international schism over the Palestinians' longtime quest for statehood, brought to the forefront on Wednesday when several countries said they would recognise a Palestinian state.

All 27 European Union countries are ICC members and EU chief diplomat Josep Borrell noted that they "are bound to execute the court's decisions".

But Khan's move exposed political differences between European powers over the conflict and their efforts to support international justice.

Britain, an ICC member since 2001 which backed Khan's bid to become prosecutor, had sought ways together with G7 counterparts to prevent the ICC from issuing "problematic" warrants for Israelis, one diplomatic source said.

"I don't believe for one moment that seeking these warrants is going to help get the hostages out, it's not going to help get aid in and it's not going to help deliver a sustainable ceasefire," Foreign Secretary David Cameron told Britain's upper house of parliament on Tuesday.

"And as we've said from the outset, because Israel is not a signatory to the (ICC's founding) Rome statute and because Palestine is not recognised as a state, we don't think that the court has jurisdiction in this area," he added.

While Israel is not a member of the ICC and rejects its jurisdiction, the court admitted the Palestinian territories in 2015 and Khan says his office has jurisdiction over the events since Oct. 7 in Israel and the Gaza Strip.

Italian Foreign Minister Antonio Tajani told local TV on Monday he opposed equating the crimes of Hamas - an Islamist movement sworn to Israel's destruction - on Oct. 7 to the response of the military of a democratically elected government.

He told Corriere della Sera daily on Tuesday that an ICC warrant could "fuel antisemitism." An Italian Foreign Ministry official said any coordinated response by European states is unlikely because of differing views on the ICC and Israel.

Foreign Minister Micheál Martin of Ireland said "it is vital that we respect the independence and impartiality of the ICC", while Czech Prime Minister Petr Fiala said the prosecutor's request was "appalling and completely unacceptable".

In a statement, France said it had for months "been warning of the need for strict compliance with international humanitarian law, and in particular of the unacceptable level of civilian casualties" in Gaza.

The French Foreign Ministry added that it "supports the International Criminal Court, its independence and the fight against impunity in all situations".

Spain's Deputy Prime Minister Yolanda Díaz, also posting on social media, welcomed the "good news" of the ICC prosecutor's request. "International law must apply to everyone. We have been calling for months for support for their investigation."

Spain's cooperation with the ICC arrest warrants is anchored in domestic law and executing them is "automatic" through Interpol, a government source said on condition of anonymity.

Israel and Palestinian leaders have dismissed allegations of war crimes, and representatives of both sides criticised Khan's decision.

ICC INDEPENDENCE

Anthony Dworkin, senior policy fellow at the European Council on Foreign Relations, said the request for warrants in itself could limit any travel plans for Netanyahu and Gallant.

All 124 member states are required to arrest wanted fugitives from the ICC, he said.

"It would be especially damaging if European countries fail to observe arrest warrants, as they have always been among the court's most active supporters," he said.

"It is vital for the credibility of European claims to support the rule of law that European officials do nothing to undermine or condemn the ICC's actions, or suggest that democratic countries should be above the law."

The ICC has no police force, so the arrest of suspects must be carried out by member or cooperative states. In 2015, South Africa let then-Sudanese leader Omar al-Bashir walk away even though the ICC wanted him for alleged war crimes and genocide.

The Netherlands, an outspoken ally of Israel which hosts an array of international courts in The Hague, declined to answer specific questions about whether it would act upon a possible warrant in the Israel-Hamas conflict.

(Reporting by Anthony Deutsch, Andrew MacAskill, Andreas Rinke; additional reporting by Charlotte Van Campenhout in Amsterdam, Stephanie van den Berg in The Hague, Elizabeth Piper in London, Tassilo Hummel in Paris, Belén Carreño in Madrid, Angelo Amante in Rome and Jan Lopatka in Prague; editing by Mark Heinrich)

By Anthony Deutsch, Andreas Rinke and Andrew MacAskill