US President Joe Biden has stressed the necessity to protect civilians in the Gaza Strip during talks with Israeli Prime Minister Benjamin Netanyahu.

The White House says the two leaders held talks over the phone on Thursday. This comes as Israel is advancing its ground invasion from the northern to southern part of Gaza, targeting Hamas.

Biden expressed his deep concern for the hostages that remain in Gaza. The two leaders agreed to stay engaged to free the remaining hostages.

The US president emphasized the critical need to protect civilians and to separate the civilian population from Hamas including through corridors that allow people to move safely from "defined areas of hostilities."

Biden welcomed the recent Israeli decision to allow requisite levels of fuel into southern Gaza, but stressed that much more assistance is urgently required.

He also reiterated his concern about "extremist violence" committed against Palestinians in the West Bank.