President Joe Biden has stressed United States support for Israel as it mourns the killing of more than 1000 people in attacks by Hamas.
US President Joe Biden has denounced Hamas, calling the surprise attack on Israel launched by the Palestinian militant group "an act of sheer evil," and stressed support for Israel as it mourns the killing of more than 1000 people, including at least 14 US citizens.
The president also voiced concern for US citizens being held hostage by Hamas, whose stated purpose, he said, is to "kill Jews".
"There are moments in this life, and I mean this literally, when the pure unadulterated evil is unleashed on this world.
The people of Israel lived through one such moment this weekend," Biden told reporters at the White House.
Biden described what he called "stomach turning" reports of "parents butchered," "babies being killed," "entire families slain" and "women raped, assaulted and paraded as trophies".
He said Hamas had threatened to execute hostages, including survivors of the Nazi Holocaust, in violation of "every code of human morality".
He said the group's brutality and "blood thirstiness" is a reminder of the "worst rampages of ISIS".
"This is terrorism but sadly for the Jewish people, it's not new," Biden said.
The incident had brought to the surface memories of anti-semitism and the genocide of the Jewish people, he added.
In an apparent reference to Iran and Iranian-backed groups such as Lebanon's Hezbollah, Biden said he had a message for any country or organisation thinking of taking advantage of the situation - "I have one word: don't."
Israel pounded the Gaza Strip on Tuesday with the fiercest air strikes in its 75-year-old conflict with the Palestinians, razing whole districts despite a threat from Hamas militants to execute a captive for each home hit without warning.
Biden spoke after his third phone call in four days with Israeli Prime Minister Benjamin Netanyahu.
The president said he told Netanyahu "our response would be swift, decisive and overwhelming" if the US had been attacked this way but that democracies must also uphold the rule of law in wartime.
He outlined in his remarks the USmilitary assistance being sent to help Israel in its fight and said he would ask Congress to take urgent action.
Biden said US citizens were being held hostage by Hamas and that he had directed his team to share intelligence to help with hostage recovery efforts.
National security adviser Jake Sullivan told reporters at a separate briefing that 20 US citizens were missing in the conflict.
The White House on Monday said it expected to fulfil additional security requests from Israel as quickly as possible.
Biden promised replenishment of interceptors used by Israel's Iron Dome missile defence system as well as ammunition in addition to redoubling US military presence in the region.