The United States is talking to Israeli officials and others about the idea of a safe passage for Gaza civilians after Israel’s air strikes following a deadly Hamas attack over the weekend, the U.S. national security adviser Jake Sullivan said on Tuesday.

“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 (25 miles) long by 10km (6 miles) wide, is home to 2.3 million people.