With little debate, Congress cleared the measure as lawmakers prepared to leave town for the August break.
"Israeli citizens are being bombarded with missile after missile," said Sen.
An earlier attempt to provide the funds faltered amid partisan gridlock over a separate measure to handle the migrant crisis at the Southwestern U.S. border.
But lawmakers from both parties are highly supportive of Israel and were eager to provide the aid.
Israel had requested the funds from the Pentagon, and Defense Secretary
More than 2,700
Though nearly 1,500 Palestinians have been killed -- most of them civilians, according to the United Nations -- Israel has lost 63 soldiers and only three civilians thanks largely to the Iron Dome system, which intercepts rockets from Gaza.
"Iron Dome has saved countless Israeli lives," Hagel said in a letter to congressional leaders.
The emergency funds are in addition to requests pending before Congress. The money will be used to accelerate production of components of the Israel-based missile defense system to "maintain adequate stockpiles," the Pentagon said.
The funding will not be offset with cuts elsewhere in the budget, as is often required for bills to win approval in Congress.