Israel announced the arrival on Tuesday of the first transport plane carrying "advanced American ammunition."
In a statement, the Israeli military said "a first plane carrying American ammunition had landed in Israel after the US said it would send new supplies of air defenses, munitions and other security assistance to its ally to battle Palestinian Hamas militants," the Jerusalem Post reported.
The army said "the ammunition is designed to inflict significant blows," adding it is in "preparation for additional scenarios."
The Israeli army expressed its gratitude "for the American backing and assistance to the Israeli Defense Forces in particular and to the state of Israel in general, during this challenging period."
The Palestinian Hamas group launched Operation Al-Aqsa Flood against Israel early Saturday, firing a barrage of rockets and infiltrating Israel by land, sea and air. It said the surprise attack was in response to the storming of the Al-Aqsa Mosque in occupied East Jerusalem and growing settler violence against Palestinians.
In retaliation, the Israeli military launched Operation Swords of Iron against Hamas in the Gaza Strip.
More than 1,900 people have been killed so far in the violence, including at least 900 Palestinians and 1,000 Israelis, according to authorities.
Israel has also cut water and electricity supplies to Gaza, worsening the blockaded enclave's already dire humanitarian situation.
Home to nearly 2.2 million people, the Gaza Strip has already been reeling under a crippling Israeli siege since 2007.
