Israeli Defence Minister Ehud Barak called US Defence Secretary Leon Penetta early Saturday to request help protecting their embassy in Cairo, hours after Eyptian protesters attacked the building.
A statement from Barak's office said he had called Panetta and President Barack Obama's Middle East advisor Dennis Ross.
The statement also said that Barak had also discussed the incident with Israeli Prime Minister Benjamin Netanyahu and Israeli defence chiefs, though it gave no further details of the conversations.
On Friday evening protesters attacked the building housing the embassy, tearing down the Israeli flag and throwing diplomatic documents marked "confidential" down into the streets below, an AFP journalist reported.
Barak's statement made no mention of any actual physical breach of the embassy.
Egyptian soldiers and military vehicles massed near the Israeli embassy in Cairo following violent protests in front of the Jewish state's mission that left more than 200 people injured.
One demonstrator died of a heart attack during the violence, which erupted not far from Tahrir Square, the epicentre of an uprising that ousted president Hosni Mubarak in February.
US President Barack Obama called on Egypt to protect Israel's embassy yesterday as the government in Cairo called an emergency meeting and the Jewish state's ambassador was reportedly at the airport in the capital awaiting a flight home.
Earlier on Friday, thousands of pro-reform protesters had massed in Tahrir Square to demand reforms and an end to military trials of civilians.
After listening to the weekly Muslim prayer, which told Egyptians it was shameful to "forget their revolution," about 1,000 people left the square and marched to the Israeli embassy several kilometres away.
Chanting "Lift your head high, you are an Egyptian," they demolished about half of the security wall outside the mission with sledge-hammers and a hefty metal bar, as military police looked on.
The wall, about two metres high, consists of prefabricated cement slabs recently installed around the building that houses the embassy overlooking a bridge in Cairo.
Motorists on the bridge adjacent honked horns in support as some protesters chanted: "To Jerusalem we will march, one million martyrs!"
A protester clambered up the embassy building and removed the flag, throwing it down to the rapturous crowd below.
But protesters later scuffled with military police when they tried to force their way down a side street near the building that had been cordoned off.
Demonstrators set fire to two police trucks and damaged four other security vehicles around the embassy building, and pelted anti-riot police with stones, an AFP journalist witnessed.
They grabbed several helmets and shields from police and at least one teargas gun, while others invaded and damaged a small police station in the neighbourhood. Gunfire was later heard in the area.
The violence left 235 injured, said a health ministry statement cited by state television, with one person having died of a heart attack.
Demonstrators broke into the Israeli embassy late on Friday, throwing thousands of pages of documents marked "confidential" into the streets, an AFP journalist reported from the scene.
The documents, some of which were written in Arabic, carried Israeli diplomatic stamps and appeared to be correspondence between Israeli officials and their Egyptian counterparts.
Obama on Friday expressed his concern as he spoke by telephone to Israeli Prime Minister Benjamin Netanyahu, the White House said in a statement.
"The president expressed his great concern about the situation at the embassy, and the security of the Israelis serving there," it said.
Relations between Egypt and Israel have been particularly tense since August 18, when Israeli troops killed five Egyptian policemen as they chased militants along the border. That incident followed a series of Negev desert ambushes that killed eight Israelis.
