The White House on Thursday pointed the finger at Israel for the shelling of a United Nations school in Gaza, calling the incident "totally unacceptable and totally indefensible."
“All evidence points to Israeli artillery as the cause," Earnest said, echoing what UN Secretary General Ban Ki-moon said about the attack earlier this week.
The school in Northern Gaza — which had been housing thousands of homeless people — came under fire on Wednesday, killing 16 people, according to multiple reports. Israeli officials said its forces were attacked by Hamas militants near the school.
The White House spokesman said Israel "can and should do more to protect the lives of innocent civilians" and said the country’s military should live up to its standards of warfare.
The Pentagon echoed that message Thursday, calling on Israel to do more to reduce civilian casualties in the conflict with Hamas.
"The Israelis have very high and public standards for the precautions that they take to protect civilian lives," said Pentagon spokesman Army Col. Steve Warren.
"Civilians casualties in Gaza have been too high, and it's become clear that the Israelis have to do more to live up to their very high and public standards for protecting civilian lives," he said.
The pressure from the U.S. comes the day after the Pentagon announced the delivery of munitions to Israeli forces.
Among the weapons being delivered are 120mm tank rounds and 40mm illumination rounds. The weapons are coming from a "war reserve" the U.S. keeps in Israel.
"There is a war reserve stockpile in Israel. The value of the current stocks there is approximately $1 billion. We will not disclose the specific types of munitions stored in that stockpile," Warren said.
The request was not an emergency request, Warren said, and although the Pentagon has various sources of weapons, officials decided to draw upon the war reserve in Israel since some of the munitions stored there were getting older and needed to be rotated out.
"We have a longstanding security cooperation agreement with Israel, part of that agreement is to provide munitions," Warren said.
Warren said there was no condition placed upon the munitions that were approved for delivery.
He said the munitions "could be used in training, they could be used in operation — they could be used for anything."
But, he made clear, "We want them to do more to live up to their high standards of reducing civilian casualties," he said.
Israel and Hamas are now locked in the fourth week of a military conflict that began on July 8.
Israel has launched an air and ground campaign to destroy underground tunnels in Gaza it says are being used by Hamas to ferry weapons and stage attacks. Hamas, in turn, is firing rockets into Israel.
Israel says in the past three weeks, Hamas has fired over 2,825 rockets at its civilians.
The U.S. and other world powers have tried to broker a permanent ceasefire in the face of mounting civilian casualties.
Gaza officials say at least 1,372 Palestinians, many of them civilians, have been killed and nearly 7,000 wounded since the fighting began.
So far, 56 Israeli soldiers have been killed, and more than 400 wounded, as well as three civilians, according to the Associated Press.
The White House has repeatedly voiced its support for Israel's right to defend itself, but has become more vocal about the civilian deaths in Gaza.
President Obama on Sunday spoke to Israeli Prime Minister Benjamin Netanyahu and urged an “immediate, unconditional" cease-fire to stop the bloodshed.
While Obama issued a “strong condemnation" of the rocket attacks against Israel, he also expressed "growing concern" about the civilian casualties in Gaza, according to the White House.
— This story was updated at 2:05 p.m.