Fears that the Israel-Hamas war might spread across the Middle East grew Sunday as the U.S. announced it was sending more military assets to the region and Israel appeared poised for a ground invasion of the Gaza Strip, a day after a peace summit in Egypt ended with little to show for it.

U.S. Defense Secretary Lloyd Austin said Washington would step up military readiness and deterrence in the Middle East while assisting in the defense of Israel in response to what he said were "recent escalations by Iran and its proxy forces" across the region.

A Terminal High Altitude Area Defense (THAAD) system and additional Patriot missile system battalions will also be sent to the region, while more troops will be put on standby, "as part of prudent contingency planning, to increase their readiness and ability to quickly respond as required," Austin said in a statement.