JERUSALEM (AP) -- Israel's cutoff of food, fuel, medicine and other supplies to Gaza's 2 million people has sent prices soaring and humanitarian groups into overdrive trying to distribute dwindling stocks to the most vulnerable.

The aid freeze has imperiled the tenuous progress aid workers say they have made to stave off famine over the past six weeks during Phase 1 of the ceasefire deal Israel and Hamas agreed to in January.

After more than 16 months of war, Gaza's population is entirely dependent on trucked-in food and other aid. Most are displaced from their homes, and many need shelter. Fuel is needed to keep hospitals, water pumps, bakeries and telecommunications -- as well as trucks delivering aid -- operating.

Israel says the siege aims at pressuring Hamas to accept its spinoff ceasefire proposal. Israel has delayed moving to the second phase of the deal it reached with Hamas, during which the flow of aid was supposed to continue. Israeli Prime Minister Benjamin Netanyahu said Tuesday that he is prepared to raise the pressure and would not rule out cutting off all electricity to Gaza if Hamas doesn't budge. Rights groups have called the cutoff a "starvation policy."

Two days in, how is the cutoff impacting Gaza on the ground?

There's no major stockpile of tents in Gaza for Palestinians to rely on during the aid freeze, said Shaina Low, communications adviser for the Norwegian Refugee Council. The aid that came in during the ceasefire's first phase was "nowhere near enough to address all of the needs," she said.

"If it was enough, we wouldn't have had infants dying from exposure because of lack of shelter materials and warm clothes and proper medical equipment to treat them," she said.

Six infants in the Gaza Strip died from hypothermia during Phase 1.

Aid groups are now trying to assess what stocks they do have in Gaza.

"We're trying to figure out, what do we have? What would be the best use of our supply?" said Jonathan Crikx, a spokesperson for UNICEF. "We never sat on supplies, so it's not like there's a huge amount left to distribute."

He predicted a "catastrophic result" if the freeze continues.

During the ceasefire's first phase, humanitarian agencies rushed in supplies and quickly ramped up their capabilities. Aid workers set up more food kitchens, health centers and water distribution points. With more fuel coming in, they were able to double the amount of water drawn from wells, according to the U.N. humanitarian coordination agency, or OCHA.

The United Nations and associated nongovernmental organizations brought in around 100,000 tents as hundreds of thousands of Palestinians tried to return to their homes, only to find them destroyed or too damaged to live in.

But the progress relied on the flow of aid continuing.

The International Organization for Migration now has 22,500 tents sitting in its warehouses in Jordan, after supply trucks brought back their undelivered cargo once entry was barred, said Karl Baker, the agency's regional crisis coordinator.

The International Rescue Commission has 6.7 tons (14,771 pounds) of medicines and medical supplies waiting to enter Gaza, the delivery of which is now "highly uncertain," said Bob Kitchen, vice president of the Emergencies and Humanitarian Action Department.

"It's imperative that aid access is now immediately resumed. With humanitarian needs sky high, more aid access is required, not less," Kitchen said.

The U.N.'s humanitarian office said Tuesday that prices of vegetables and flour shot up after the crossings closed.

Sayed Mohamed al-Dairi walked through a bustling market in Gaza City just after the cutoff was announced. Prices that had just started to come down during the ceasefire had jumped back up, as sellers hiked the prices of their dwindling wares.

"The traders are massacring us, the traders are not merciful to us," he said. "In the morning, the price of sugar was 5 shekels, ask him now, the price has become 10 shekels."

In the central Gaza city of Deir Al-Balah, one cigarette priced at 5 shekels ($1.37) before the cutoff now stands at 20 shekels ($5.49). One kilo of chicken (2.2 pounds) that was 21 shekels ($5.76) is now 50 shekels. ($13.72). Cooking gas has soared even more, from 90 shekels ($24.70) for 12 kilos (26.4 pounds) to 1,480 shekels ($406.24).

Following the Oct. 7, 2023 Hamas attack on Israel, Israel cut off all aid to Gaza for two weeks -- a measure central to South Africa's case accusing Israel of genocide in Gaza at the International Court of Justice. That took place as Israel launched the most intense phase of its aerial bombardment campaign on Gaza, one of the most aggressive in modern history.

With the ceasefire expiring and aid again frozen, Palestinians fear a repeat of that period.

"We are afraid that Netanyahu or Trump will launch a war more severe than the previous war," said Abeer Obeid, a Palestinian woman from northern Gaza.

"The crossings are the means by which people obtain the basic necessities of life, why are they closing them," she asked. "For the extension of the truce, they must find any other solution."