“We are focused on this question, there are consultations going on,” Sullivan told reporters in a White House press briefing.

Israel has battered Palestinians with deadly air strikes in Gaza after Palestinian Islamist group Hamas’ attack on Israel on Saturday that left hundreds dead.

Gaza’s health ministry said at least 830 Palestinians were killed and up to 4,250 wounded in Israeli air strikes on the blockaded enclave since Saturday. The enclave, only 40km long by 10km wide, is home to 2.3 million people.

The UN said more than 180,000 Gazans had been made homeless.

Gazans have lived under an Israeli-led blockade for 16 years, since Hamas seized control of the territory in 2007.

Israel’s embassy in Washington said the death toll from Hamas’ weekend attacks had surpassed 1,000.

Washington and some of its key Western allies have said Israel has the right to self-defence.

“We do not deliberately target civilians,” Sullivan said of the US and Israel, when asked about civilian casualties in Gaza in the Tuesday press briefing.

“We work to make sure that our military operations are conducted consistent with the rule of law and the law of war,” he added.

Palestinians in Gaza have said that Israeli bombardment has been heavy and feels like a new “Nakba,” the Arabic word for catastrophe that refers to the 1948 war of Israel’s creation that led to their mass dispossession.