Joe Biden warned on Wednesday that he “will not hand over” some weapons and ammunition to Israel, of which the US is a key ally and supplier of military equipment, especially “artillery shells”, if its forces launch a large-scale ground attack on Rafa — an unprecedented move by Washington.

“If they enter Rafah, I will not hand over the weapons that are used (…) against cities,” the Democratic president said in an interview with the CNN television network.

The invasion of Rafah would be “simply wrong” and “we will not hand over the artillery shells that are being used” by the Israeli military, Mr Biden insisted.

It is the first time that the US president, 81 years old, has set — publicly — conditions for the continuation of US military support to Israel. However, he clarified that he does not think Israel has “crossed the red line yet”, when asked about the occupation of the Gaza Strip border crossing with Egypt and the “limited” range operations it is conducting in areas of the Rafah.

“They have not entered densely populated areas,” he said, implying that if there is an attack on Rafa, he will react. “I clearly told Bibi (s.a. Israeli Prime Minister Benjamin Netanyahu) and his wartime government that they will not have our support if they go to densely populated areas,” he said.

Asked about his government’s decision last week to suspend the delivery of a shipment of bombs, he commented: “Civilians have been killed in Gaza because of these bombs,” adding “this is ugly.”

However, he emphasized that the US will continue to “guarantee that Israel is protected by Iron Dome”, the anti-missile defense system of the Israeli armed forces, which uses US-made missiles.

Joe Biden has not stopped expressing his unwavering support for Israel in its military operation in the Gaza Strip in retaliation for the unprecedented attack by Hamas’ military arm on southern sectors of the Israeli territory in October. However, his relationship with Israeli Prime Minister Netanyahu has been marked by tensions and the Rafa case threatens to cause a rift.

A senior administration official said on condition of anonymity that the delivery of “1,800 2,000-pound (907-kilogram) bombs and 1,700 500-pound (226-kilogram) bombs” to the Israeli military was suspended last week because the Netanyahu government did not allay “concerns » of Washington for civilians.

The State Department reiterated yesterday that Israel has not presented a credible plan that would guarantee the protection of civilians and their access to humanitarian aid.

Mr. Netanyahu describes Rafah as the “last” stronghold of Hamas and keeps declaring that his army will “enter” the city to “defeat” the military arm of the Palestinian Islamist movement.