US Vice President Kamala Harris calls for an “immediate ceasefire” in Gaza in Selma, Alabama. AFP

US Vice President Kamala Harris urged an immediate ceasefire in Gaza, upping the pressure on key ally Israel as heavy fighting raged in the Palestinian territory.

Harris's comments on Sunday, the most forceful to date by a US administration official, came as Washington led a push to lock in a truce before Ramadan, the Muslim fasting month that begins in around one week.

Envoys from the United States, Qatar and Hamas were in Cairo for the latest round of talks over a proposal to pause the five-month-old war.

According to a senior US official, Israel has broadly accepted the terms, which would see stepped-up aid deliveries and the exchange of hostages for Palestinian prisoners.

Several sticking points reportedly remain, including Hamas's insistence that Israeli forces entirely withdraw from the devastated territory.

"Hamas claims it wants a ceasefire. Well, there is a deal on the table," Harris said.

Taking an unusually sharp tone, she demanded Israel "do more to significantly increase the flow of aid" into Gaza, where she said people are starving and the conditions "inhumane".

"Given the immense scale of suffering in Gaza, there must be an immediate ceasefire."

Pressure for a truce has mounted after attempted aid deliveries have descended into scenes of tragedy, and convoys have failed to reach families gripped by food shortages in the north.

After UN warnings of famine in Gaza, the United States started airdropping food rations on Saturday, following in the steps of Jordan and some other countries.

"It is imperative that we expand the flow of aid into Gaza to alleviate the dire humanitarian situation," US Secretary of State Antony Blinken wrote on social media platform X on Sunday.

Agence France-Presse