Biden says civilian deaths 'price of waging war,' denies Palestinian death toll

US President Joe Biden on Wednesday appeared to question the number of people killed in Gaza by Israel, amid Tel Aviv's brutal assault on the besieged Palestinian enclave.

More than 6,500 Palestinians - mostly civilians - have been killed in Israel's strikes on Gaza since October 7, while 1,400 Israelis have been killed.

"I have no notion that the Palestinians are telling the truth about how many people are killed. I'm sure innocents have been killed, and it's a price of waging war," Biden told reporters in the White House's Rose Garden.

"But I have no confidence in the number that the Palestinians are using."

The president also reiterated his backing of Israel's brutal assault on Gaza.

"Israel has a right, and I would add responsibility, to respond to the slaughter of its people," Biden said, repeating a mantra that has echoed among Israel's Western allies.

Biden accused Hamas of "hiding behind" Palestinian civilians - an accusation often repeated by Israel - but said Tel Aviv must follow the "laws of war."

"Israel has to do everything in its power, as difficult as it is, to protect innocent civilians. It's difficult," he said.

Biden also called for an immediate end to Israeli settler attacks on Palestinians in the West Bank.

"That's pouring gasoline on the fire," he said. "They're attacking Palestinians in places that they're entitled, and... it has to stop now."