Donald Trump issued a sharp ultimatum to Hamas as the second phase of the US-brokered ceasefire with Israel kicked off. On Thursday night, Trump posted on Truth Social demanding "Hamas must IMMEDIATELY honor its commitments, including the return of the final body to Israel, and proceed without delay to full Demilitarization." He warned Hamas they could choose "the easy way, or the hard way." So far, Hamas refuses to give up its weapons. Trump and his allies plan to dismantle Hamas' heavy arsenal and tunnels with help from Egypt, Turkey, and Qatar. The US also considers a "buy-back" scheme for smaller arms like rifles and pistols. The ceasefire's second phase shifts focus from just stopping fighting to rebuilding Gaza, demilitarising Hamas, and setting up transitional governance. Trump said he will lead a "board of peace" to supervise Gaza's reconstruction and recovery. Former UK Prime Minister Tony Blair and former UN envoy Nickolay Mladenov are also involved. This board will oversee a 15-member Palestinian group running Gaza's civil affairs during transition. Meanwhile, violence continues despite the ceasefire. On Thursday, six Palestinians died in Israeli airstrikes at al-Aqsa Martyrs hospital area. Harsh winter storms recently killed at least four displaced Palestinians when tents collapsed. The UN says Gaza faces an enormous cleanup with over 60 million tonnes of rubble, likely needing seven years to clear. The UN estimates reconstruction could cost over $70 billion. UN officials stress urgent early recovery to restore basic services amid ongoing hardship. The ceasefire has reduced but not ended fighting. Since October, at least 451 Palestinians and 100 children have died. UNICEF reported six children died of cold during this time. The fragile peace faces big challenges ahead.