US President Joe Biden has warned Israeli Prime Minister Benjamin Netanyahu that US policy with respect to Gaza will depend on the swift implementation of new steps to protect civilians and aid workers.

In a phone call with Netanyahu on Thursday, Biden made clear the need for Israel to announce and implement a series of concrete steps to address civilian harm, humanitarian suffering and the safety of aid workers.

The call followed an Israeli airstrike that killed seven members of the US-based aid group World Central Kitchen in Gaza earlier this week.

The White House said Biden told Netanyahu that strikes on humanitarian workers and the overall humanitarian situation are "unacceptable."

Biden emphasized that an immediate ceasefire is essential to stabilize and improve the humanitarian situation and protect innocent civilians.

The two leaders also discussed Iranian threats against Israel and the Israeli people.

White House National Security Communications Advisor John Kirby said after the phone call that the US wants to see "real changes" on the Israeli side.

Kirby added that the US hopes to see a dramatic increase in the humanitarian assistance going into Gaza, and a reduction in the violence against civilians and aid workers in the "coming hours and days."