Biden, who landed in Israel and met Prime Minister Benjamin Netanyahu early on Wednesday, said Hamas was worse than Islamic State for its killings of Israeli civilians in the surprise attack on Oct. 7 which triggered the latest Israel-Palestinian violence.

He said he was "sad and outraged" by an explosion at a hospital in the Gaza Strip on Tuesday which Hamas said killed hundreds of people.

"Based on what I've seen, it appears as though it was done by the other team, not you. But there's a lot of people out there not sure, so we've got a lot -- we've got to overcome a lot of things," Biden said.

Israel says the blast was caused by a Palestinian rocket that fell short. Hamas denies that. The bloodshed there has stoked already fierce anti-Israel protests in the region.

Biden said 31 Americans were among the more than 1,300 Israelis killed in Hamas's Oct. 7 attack.

(Reporting by Dan Williams, Crispian Balmer, John Davison in Jerusalem, Editing by Angus MacSwan)