US Defense Secretary Lloyd Austin urged Israel to protect civilians during the urban fight against Hamas.

Austin told the Reagan National Defense Forum in California that he had “learned a thing or two about urban warfare” while fighting in Iraq and leading the campaign against Daesh.

“Like Hamas, Daesh was deeply embedded in urban areas. And the international coalition against Daesh worked hard to protect civilians and create humanitarian corridors, even during the toughest battles,” Austin said.

“The lesson is not that you can win in urban warfare by protecting civilians. The lesson is that you can only win in urban warfare by protecting civilians,” he said.

Meanwhile, fighting between Israel and Hamas resumed the day before after a week-long truce between the two sides collapsed, with both sides blaming the other for the breakdown of the deal and the resumption of violence.