A Dutch court on Monday ordered the government to block all exports of F-35 fighter jet parts to Israel over concerns they were being used to violate international law during the war in Gaza.

The appeals court said the state had seven days to comply to the order, which echoed alarm across Europe and elsewhere over the humanitarian impact of the war. Israel denies committing abuses and says it is battling Hamas militants bent on its destruction.

"It is undeniable that there is a clear risk the exported F-35 parts are used in serious violations of international humanitarian law," the court said, ruling in favour of a lawsuit against the Dutch state over the exports brought by rights groups including the Dutch arm of Oxfam.

The Dutch government said it would appeal to the Supreme Court, arguing that it should be up to the state to set foreign policy, not a court.

Dutch Trade Minister Geoffrey van Leeuwen said the fighter jets were crucial for Israel's security and it was too early to say if a ban on exporting parts from his country would have any concrete impact on the overall supplies to Israel.

"We are part of a big consortium of countries that are also working together with Israel. We will talk to partners how to deal with this," he said.

The Netherlands houses one of several regional warehouses of US-owned F-35 parts, which are distributed to countries that request them, including Israel in at least one shipment since Oct 7.

Israel's massive aerial and ground offensive in the densely populated Gaza Strip has killed more than 28,000 Palestinians, according to the Hamas-run enclave's health authorities, and forced most of its 2.3 million people to flee their homes.

Israel denies committing war crimes in its attacks on Gaza, which followed the Hamas cross-border raid on southern Israel on Oct 7 in which 1,200 Israelis were killed and around 240 were taken hostage.

Israeli cabinet minister Benny Gantz said on social media he had met with visiting Dutch Prime Minister Mark Rutte and welcomed the decision to appeal.

"I ... reiterated that the court decision will harm the global and Israeli imperative of fighting terror," Gantz posted on X.

CIVILIAN CASUALTIES

In a first ruling in December, a Dutch lower court had stopped short of ordering the Dutch government to halt the exports, even though it said it was likely that F-35s contributed to violations of the laws of war.

But where the lower court ruled the state had a large degree of freedom in weighing political and policy issues to decide on arms exports, the appeals court said such concerns did not trump the clear risk of breaches of international law.

The appeals court also said it was likely the F-35s were being used in attacks on Gaza, leading to unacceptable civilian casualties. It dismissed the Dutch state's argument that it did not have to do a new check on the permit for the exports.

"We hope this ruling will strengthen international law in other countries so that the citizens of Gaza are also protected by international law," Oxfam Novib director Michiel Servaes said in a statement.

European Union foreign policy chief Josep Borrell noted the ruling on Monday and made a thinly veiled call on the United States to cut arms supplies to Israel due to high civilian casualties in Gaza.

Presiding Judge Bas Boele said there was a possibility the Dutch government could allow the export of F-35 parts to Israel in future, but only on the strict condition they would not be used in military operations in Gaza.

The government said it would try to convince partners it would remain a reliable member of the F-35 programme and other forms of international and European defence cooperation.

The F-35's manufacturer, Lockheed Martin said in a statement it was evaluating the impact of the Dutch court ruling on its supply chain but added it stood "ready to support the US government and allies as needed".