Shortly after Witkoff's arrival on Thursday, President Donald Trump posted on his Truth Social network: "The fastest way to end the Humanitarian Crises in Gaza is for Hamas to SURRENDER AND RELEASE THE HOSTAGES!!"
The US State Department also announced sanctions on officials of the Palestinian Authority and the Palestine Liberation Organisation, saying the groups were undermining peace efforts. It was Washington's latest apparent diplomatic shift backing Israel against the Palestinians and diverging from its European allies.
The PA and PLO, rivals of the Hamas fighters that control Gaza, are internationally accepted as the representatives of the Palestinian people and administrators of a Palestinian state that France, Britain and Canada have said in recent days they could soon recognise as independent.
A spokesperson for the Palestinian Authority did not immediately respond to a request for comment. The full impact of the US move was not immediately clear: the State Department said targeted individuals would be barred from travelling to the United States but did not identify those targeted.
Witkoff arrived in Israel with Netanyahu's government facing mounting international pressure over the widespread destruction of Gaza and constraints on aid in the territory.
Following the meeting, a senior Israeli official said an understanding between Israel and the US was emerging that there was a need to move from a plan to release some of the hostages to a plan to release all the hostages, disarm Hamas, and demilitarise the Gaza Strip.
The official did not provide details on what that plan would be, but added Israel and the United States will work to increase humanitarian aid, while continuing the fighting in Gaza.
Witkoff will travel to Gaza on Friday to inspect food aid delivery as he works on a final plan to speed deliveries to the enclave, the White House said.
Gaza medical officials said at least 23 people were reported killed by Israeli fire across the enclave, including 12 people among crowds who had gathered to receive aid around the Netzarim corridor, an area held by Israeli troops in central Gaza.
The Israeli military said its troops had fired warning shots to disperse crowds, and had not identified any casualties.
Since the war began, the Gaza health ministry has recorded 156 deaths from starvation and malnutrition, most of them in recent weeks, including at least 90 children.
Confronted by rising international outrage over images of starving children, Israel said on Sunday it would halt military operations for 10 hours a day in parts of Gaza and designate secure routes for convoys delivering food and medicine.
With the number of Palestinians killed in almost two years of war passing 60,000 this week, pressure has been mounting in Gaza on Hamas to reach a ceasefire deal with Israel.
Hamas is still holding 50 hostages in Gaza, of whom around 20 are believed to be alive. Mothers of hostages led a protest outside Netanyahu's office, calling on the government to end the war.
Netanyahu, whose ruling coalition includes two far-right parties that want to conquer Gaza and re-establish Jewish settlements there, has said he will not end the war until Hamas no longer rules the enclave and lays down its arms. Hamas has rejected calls to disarm.
Israel has denounced declarations by France, Britain and Canada since last week that they may recognise a Palestinian state, which Israel says amounts to rewarding Hamas for its October 7, 2023, assault on Israeli territory.
That attack, in which fighters killed 1200 people and took 251 hostages back to Gaza, precipitated the war.
