As Joe Biden arrived in Israel to express his solidarity and discuss war plans with its leaders, the high-stakes visit has been overshadowed by a blast at a crowded Gaza hospital in which hundreds are feared to have died.
The blast, which Palestinian and Israeli officials have blamed on each other, has further stoked tensions.
Mr Biden had planned to travel from Israel to Jordan to meet Arab leaders, but that leg of the trip was cancelled after the deaths in Gaza on Tuesday inflamed tensions and sparked protests.
Mr Biden and Mr Netanyahu held a joint news conference shortly after he arrived, and the US president is expected to meet the Israeli war cabinet later on Wednesday.
He will ask “tough questions” to better understand Israel’s war aims and objectives in Gaza, US National Security Council spokesman John Kirby said.
“He’ll be asking some tough questions but he’ll be asking them as a friend,” Mr Kirby told reporters, adding that the US would stress the need for humanitarian aid to enter Gaza and the obligation to avoid civilian casualties
Mr Biden will also meet emergency workers who responded to the unprecedented attack by the Hamas Palestinian militant group which left 1,300 Israelis dead on 7 October. Hamas gunmen breached the border and infiltrated Israeli communities close to Gaza.
He will also meet some of those who lost loved ones or whose family members are being held hostage, officials said.
Israel has asked the US for $10bn (£8.2bn) in emergency military aid following the attack, the BBC’s US partner CBS News reported, quoting what it called sources familiar with the request.
The Hamas-led authorities in Gaza say 500 people died in the explosion at the Al Ahli hospital on Tuesday, which one doctor called “a massacre”.
Hamas blamed Israel, calling it a “war crime”. A spokesperson for Palestinian Authority President Mahmoud Abbas, who is based in the occupied West Bank, accused Israel of a “heinous crime”.
But Israel said the blast was caused by rockets misfired by another group, Palestinian Islamic Jihad.
“Our intelligence is reporting to us that apparently there was a rocket launched by Islamic Jihad,” Mark Regev, a spokesman for Mr Netanyahu, told the BBC.
