World leaders and humanitarian groups said on Friday that Israel must show concrete results after it reacted to growing pressure from the United States by announcing it would open more aid routes into the Gaza Strip, where the United Nations has warned that a famine is looming.

At a news conference in Brussels on Friday, Secretary of State Antony J. Blinken welcomed the new aid routes, calling them “positive developments,” but said that the United States was watching to see if Israel would make it a priority to ease the humanitarian crisis in Gaza. One measure of Israel’s commitment, he said, will be “the number of trucks that are actually getting in on a sustained basis.”

“The real test is results, and that’s what we’re looking to see in the coming days and the coming weeks,” he said, adding, “Really, the proof is in the results.”

Germany’s foreign minister, Annalena Baerbock, called on Israel to open the new aid routes “quickly.”

Israel said early Friday that it had agreed to open the Erez crossing to allow aid into northern Gaza, where hunger is particularly severe; to use the Israeli port of Ashdod to direct more aid into the enclave; and to significantly increase deliveries from Jordan.

It made the announcement hours after President Biden suggested in a phone call with Prime Minister Benjamin Netanyahu that further American support for Israel would depend on its taking action to protect civilians and aid workers in Gaza and to alleviate the hunger crisis there.

While some Gazans said they had heard recently that more aid was flowing through existing routes, it was still not nearly enough to feed their families.

“We are clinging to life, and that’s it,” said Mohammad al-Masri, a 31-year-old accountant. He was sheltering with his family in a tent in Rafah, a city crowded with hundreds of thousands of uprooted Gazans that Israel has promised to invade in its campaign to destroy Hamas. He said his family was able to buy some canned meats and vegetables and obtain rice and beans from a charity.

“The aid doesn’t always get to those who are displaced, except for very little,” he said Friday in a message on WhatsApp. “Mostly it all gets sold in the market,” he added, echoing what many Gazans have said for months.

Friday was a holy day for Muslims observing Ramadan, a day that would normally bring increased religious observance and preparations for Eid al-Fitr festivities marking the end of Ramadan. But Mr. al-Masri said there was none of that in the tent encampment he was living in.

“Most people fast because there is nothing to eat anyway,” he said. “We didn’t feel like this was Ramadan.”

Since the start of the war, Israel has limited aid entering Gaza to two tightly controlled border crossings at Kerem Shalom and Rafah. Aid groups have said they face enormous challenges trying to move supplies through those crossings, including lengthy Israeli inspections and the risk of Israeli strikes on their workers in Gaza.

Global outrage at Israel reached new heights this week after Israeli drone strikes killed six foreign nationals and a Palestinian who were working for the charity group World Central Kitchen and traveling in three vehicles in central Gaza.

After the attack, the World Central Kitchen suspended its operations in Gaza, and other humanitarian groups and officials from the United States, Britain and other countries said Israel must do more to ensure the safety of aid workers.

The World Food Program, an arm of the United Nations, said on Friday that it would ask Israel to clarify security and logistical arrangements for the new routes “so we can move swiftly to exploit any new opportunity to feed more Gazans as famine takes hold.”

Israeli officials did not immediately make clear when the new routes would open or how much aid could pass through them. The Erez border crossing into northern Gaza in particular could present logistical hurdles since most of the humanitarian aid has been stored in Egypt, on the opposite side of the coastal enclave.

Charles Michel, the president of the European Council, said that the new measures were simply “not enough” and that “urgent efforts are required to immediately end hunger.”

“Gazan children and infants are dying of malnutrition,” he wrote on social media.

At a meeting of the United Nations Security Council on Friday, Riyad H. Mansour, the Palestinian ambassador to the U.N., pointed out that Israel’s reaction to the deaths of the World Central Kitchen workers was starkly different from its reaction to the deaths of Palestinians.

He noted that Israel swiftly investigated the attack on the charity group’s convoy and then removed two officers and reprimanded three senior commanders for their roles in it.

“Who will be held accountable for all the tens of thousands of Palestinian civilians killed?” he said, alluding to the more than 32,000 Gazans who have been killed, according to the territory’s health officials. “Are our lives not worthy of holding accountable those who murder us and kill us in large numbers?”

Gilad Erdan, Israel’s ambassador to the United Nations, expressed condolences for the deaths of the World Central Kitchen workers but said the strikes on their convoy were a “tragic mistake made due to Hamas’s cynical modus operandi to exploit civilian infrastructure and vehicles.”

“Israel never targets civilians deliberately — never — let alone aid workers carrying out crucial work,” he told the council.

The council debate in New York played out as the U.N.’s top human rights panel in Geneva adopted a resolution on Friday that called on all countries to stop supplying arms to Israel, warning of possible violations of international humanitarian law and human rights abuses.

The panel, the Human Rights Council, approved the resolution by a vote of 28 to 6, with 13 states abstaining. The United States and Germany, Israel’s biggest arms suppliers, voted against the measure, though the U.S. ambassador to the council, Michèle Taylor, criticized Israel’s prosecution of the war.

“Israel has not done enough to mitigate civilian harm,” Ms. Taylor said before the vote, calling for an immediate cease-fire and urging Mr. Netanyahu to negotiate a deal with Hamas.

Israel’s representative on the panel, Meirav Eilon Shahar, condemned the passage of the resolution as a “very dark day in the history of the council.” Noting that the resolution did not denounce Hamas for attacking Israel on Oct. 7, she said the panel had “turned a blind eye” to acts of violence against Israelis.

Later, the Israeli Foreign Ministry issued a statement noting that the council had disregarded the supply of weapons to Hamas from Iran and its allies.

Ultimately, many world leaders have said that a cease-fire would be the surest way to get more aid into Gaza and to free hostages still being held there. But talks aimed at reaching such a deal have been stalled for weeks.

In an effort to help the parties reach an agreement, the C.I.A. director, William J. Burns, was expected to travel to Cairo on Saturday to meet with his Israeli counterpart, David Barnea, and with Qatari and Egyptian officials, who have been mediating with Hamas, according to two people briefed on the plans.

Reporting was contributed by Nick Cumming-Bruce, Matina Stevis-Gridneff, Gaya Gupta, Johnatan Reiss and Julian E. Barnes.