Israel has called up military reservists to brace for a possible reeruption of war in the Gaza Strip if Hamas fails to meet a Saturday deadline to free further Israeli hostages and a nearly month-old ceasefire unravels.

Concern that the truce will collapse is growing as fury mounts in the Arab world over President Donald Trump's plan for the United States to take over Gaza, resettle its Palestinian inhabitants and build an international beach resort.

Hamas said Egypt and Qatar, which with U.S. support mediated the ceasefire deal that took effect on Jan. 19, had stepped up efforts to break the impasse, and the Palestinian militant group's Gaza chief, Khalil Al-Hayya, arrived in Cairo for talks.