Israeli military blamed Palestinian militants, saying an outgoing Islamic Jihad rocket misfired to Gaza.
US President Joe Biden on a solidarity visit to Israel Wednesday backed the ally's account that Palestinian militants caused a devastating hospital strike in Gaza, adding Hamas had brought "only suffering".
"I was deeply saddened and outraged by the explosion at the hospital in Gaza yesterday. And based on what I've seen, it appears as though it was done by the other team, not you," Biden said as he opened a meeting with Prime Minister Benjamin Netanyahu in Tel Aviv.
"But there's a lot of people out there not sure so we have to overcome a lot of things," Biden said.
Health authorities in Hamas-ruled Gaza said the explosion killed between 200 and 300 people and was caused by the latest in a wave of Israeli air strikes.
The Israeli military blamed Palestinian militants, saying an outgoing Islamic Jihad rocket misfired and that it would provide evidence.
"We have to bear in mind that Hamas does not represent all the Palestinian people and has brought them only suffering," Biden said.
Biden said he was encouraging Netanyahu to ensure "life-saving capacity to help the Palestinians who are innocent and caught in the middle of this".
In announcing Biden's visit, Secretary of State Antony Blinken said that Israel had agreed to work with the United States on a plan to let aid into Gaza, which has been besieged and bombarded for 12 days and under an Israeli blockade for 17 years.
Israel is threatening a ground invasion following the devastating October 7 assault by Hamas militants.
Biden said he was "proud" to visit Israel.
"I want to say to the people of Israel -- their courage, their commitment and their bravery is stunning," Biden said.