The European Union demanded Tuesday that Israel and Hamas halt their conflict in Gaza, as the world's top diplomats scrambled to find a solution to the escalating bloodshed.

While Israel's Defence Minister Ehud Barak said he was "considering favourably" the idea of a break in fighting to allow aid into the besieged enclave, Europe called for an "immediate and permanent ceasefire".

European foreign ministers met in Paris to urge a truce, while the Middle East diplomatic Quartet -- the EU, Russia, United Nations and United States -- made a similar call for calm after a conference call.

"There must be an unconditional halt to rocket attacks by Hamas on Israel and an end to Israeli military action," the EU statement said.

The EU said it intended to work alongside the Quartet to seek peace, and added: "In this respect, it has been agreed that a European ministerial delegation will travel to the region shortly."

Earlier, some EU officials had suggested that the body would as a priority ask Israel for a temporary halt in its bombardments to allow humanitarian aid to reach Gaza's 1.5 million beleaguered residents.

Israeli officials said they would consider international calls for a pause in fighting to allow humanitarian aid into Gaza, but both they and their Hamas opponents have rebuffed previous calls for a lasting truce.

"The minister is considering favourably the proposal for a ceasefire for humanitarian purposes," said Barak's spokesman Moshe Ronen. "This doesn't stop us in any way from preparing for a ground offensive."

France's President Nicolas Sarkozy is to meet Israeli Foreign Minister Tzipi Livni on Thursday in Paris, the French leader's office said.

Foreign capitals largely agreed on the need for both sides to halt the bombardments, though Germany and the United States have blamed the fighting squarely on the Palestinian Islamist Hamas movement.

UN Secretary General Ban Ki-moon was joined on a conference call by foreign ministers Sergei Lavrov of Russia, Condoleezza Rice of the United States and Bernard Kouchner of France.

The Quartet's peace envoy, Tony Blair, was also on the call along with EU foreign policy chief Javier Solana.

Afterwards, the UN issued a statement giving their officials' account of the call, while Quartet members made no joint statement themselves, perhaps suggesting they had been unable to agree on the wording.

"The Quartet principals... called for an immediate ceasefire that would be fully respected," the statement said.

"They called on all parties to address the serious humanitarian and economic needs in Gaza and to take necessary measures to ensure the continuous provision of humanitarian supplies," it added.

The United States backs Israel's right to defend itself and Israel has warned of a long campaign ahead, with some senior officials openly declaring that the offensive aims to topple Gaza's Hamas administration.

Such statements have undermined hopes of a quick end to the bloodshed that has already left more than 370 Palestinians -- around a sixth of them civilians -- and four Israelis dead since Saturday.

Europe also proposed a concrete measure to calm nerves: the revival of an EU observer mission to the Rafah border crossing between Gaza and Egypt.

Egypt temporarily opened the checkpoint to allow wounded Palestinians out of Gaza, but Europe would like to oversee a more permanent arrangement to allow in aid and end the Hamas-controlled territory's isolation.

Egypt's President Hosni Mubarak said the Rafah crossing would remain closed until the Palestinian president, Mahmud Abbas, regained control of Gaza from his Hamas rivals and EU observers were deployed.

"The cessation of fighting should allow lasting and normal opening of all border crossings," the statement said.

"The European Union is ready to re-dispatch" monitors "to Rafah to enable its re-opening, in cooperation with Egypt, the Palestinian Authority and Israel," it continued.

Abbas' Palestinian Authority currently has no control over Rafah, having lost control of Gaza to Hamas, and it was not clear how the EU mission could be revived while the Islamist group remains in charge.

On Sunday, the UN Security Council approved a non-binding statement calling for "an immediate halt to all violence" in Gaza and urging all sides "to stop immediately all military activities."

Nevertheless, Hamas has fired more than 250 rockets into Israeli territory and scores of Israeli air strikes have taken a mounting toll.

The crisis erupted on December 19 when a ceasefire between Hamas and Israel expired. The Palestinian group refused to renew the truce and stepped up rocket attacks on Israeli civilian targets. Israel launched its air raids on Saturday.