WASHINGTON, D.C. — President Joe Biden on Thursday called for an “immediate cease-fire” in Gaza, telling Israeli Prime Minister Benjamin Netanyahu that future U.S. support for the country’s military offensive will depend on whether Israel takes concrete steps to protect civilians and humanitarian workers in the Palestinian enclave.

The president’s comments are the first time he has threatened conditioning aid to the U.S.’s strongest ally in the Middle East during the last six months of violence in Gaza.

In a call with the prime minister, the first since March 18, Biden said that the current humanitarian crisis in Gaza is “unacceptable” and that Israel must announce and implement “measurable steps to address civilian harm, humanitarian suffering and the safety of aid workers,” according to a readout from the White House.

“He made clear that U.S. policy with respect to Gaza will be determined by our assessment of Israel’s immediate action on these steps.”

Just hours after Biden’s call, an Israeli official told Axios that the country’s security cabinet has approved opening the Erez crossing in northern Gaza for the first time since Oct. 7 in order to allow more humanitarian aid to enter the enclave.

The cabinet also reportedly approved temporarily opening up the Ashdod port to transport additional aid into Gaza, and will increase the amount of humanitarian assistance coming from Jordan via the Kerem Shalom crossing.

The Times of Israel confirmed the moves, which is an admission by Israel that it was not previously doing everything in its power to allow life-saving aid into Gaza.

Vice President Kamala Harris, Secretary of State Antony Blinken and National Security Advisor Jake Sullivan were all also on the call, but did not participate.

“I was on the conversation between President Biden and Prime Minister Netanyahu. The conversation was honest,” Harris said, according to Axios.

“The president made it clear that the U.S. will not leave Israel without the ability to defend itself,” she continued. “But if there is no change in their approach, then there will be a change in our approach.”

On Thursday, National Security Council spokesperson John Kirby declined to clarify to reporters the specific steps the U.S. wants to see Israel take, only bringing up vague previously stated measures.

In his call with Netanyahu, Biden also called for an immediate, but not permanent, cease-fire. The president has previously demanded a cease-fire in Gaza, but only as part of negotiations to free the hostages taken by Hamas militants during the deadly Oct. 7 attack on Israel.

But when asked by HuffPost, Kirby said the president’s latest call for a cease-fire was a standalone and not conditioned on a hostage deal — a new development in Biden’s approach to Gaza.

“We want to see that immediate cease-fire [in] place,” Kirby said, adding that a pause in Israel’s military offensive would stabilize the situation for innocent civilians and aid workers.

“So that we can get more humanitarian assistance and create a set of conditions where aid organizations feel better about operating inside Gaza, because as we’ve already seen as a result of the attack on the [World Central Kitchen] workers that some aid organizations are now pulling back.”

According to Kirby, the call was a direct result of Israel’s attack on a convoy with the international charity World Central Kitchen. Israeli forces launched multiple airstrikes on Monday that killed seven aid workers who had just distributed food to starving Palestinians.

The attack drew swift backlash; WCK founder and chef José Andrés accused Israel of deliberately killing his workers, one of whom was a U.S. citizen.

After the attack, the president said in a statement that he was “outraged and heartbroken” by the workers’ deaths and called out Israel for failing to “protect aid workers trying to deliver desperately needed help to civilians.”

The statement was a shift from Biden’s usually vague but supportive comments on Israel’s military decisions, however this week was not the first time the president warned Netanyahu’s government to minimize civilian casualties. Between October and January, Biden pressed the Israeli leader at least seven times to exercise more restraint during military missions in Gaza.

Despite the White House’s increasingly critical rhetoric on Israel and Thursday’s threat, Biden still has not actually changed the U.S. policy of unconditionally supporting Israel’s military. In fact, the Biden administration agreed to transfer more bombs to Israel on the same day that the country’s military killed WCK’s aid workers.

The State Department approved the transfer of more than 1,000 MK82 500-pound bombs, more than 1,000 small-diameter bombs and fuses for MK80 bombs, The Washington Post first reported. The Biden administration maintained that the approval was made prior to knowing about the WCK attack, though the State Department would not answer HuffPost’s question about whether the administration would not have approved the bombs if they knew about the attack beforehand.

“We haven’t really sent emergency aid and military assistance to Israel [after the first two months],” Kirby said, adding that the bomb approvals were not tied to the current offensive in Gaza.

Foreign military sales is a process that can take years, Kirby continued, saying that the U.S. still has an “ironclad commitment” to assist Israel in defending itself.

“What the American people want is a change in policy, not just a change in rhetoric. President Biden must not wait to see how many more innocent people the far-right Israeli government kills before he decides to change course,” said Nihad Awad, national executive director of Muslim American civil rights group CAIR.

“The Israeli government’s slaughter of over 33,000 Palestinians, several Israeli hostages waving white flags, and of World Central Kitchen aid workers is more than enough reason for President Biden to stop enabling the Israeli government’s genocidal war on everyone in Gaza right now, without delay.”