ROME (AP) — A half-billion-dollar funding shortfall for the UN relief agency for Palestinians risks cutting critical services that could "push the suffering in disastrous and unpredictable directions," the UN chief warned on Thursday. Secretary-General Antonio Guterres addressed an emergency funding conference in Rome after the US administration this year slashed tens of millions to the UN Relief and Works Agency, prompting the greatest funding crisis in its 68-year history. The agency, the oldest and largest UN relief programme in the Middle East, provides healthcare, education and social services to an estimated 5 million Palestinians in the West Bank, Gaza Strip, Jordan, Syria and Lebanon. Guterres told the conference, which was sponsored by Jordan, Egypt and Sweden, that investment in UN programmes addresses the despair and other factors "that lead to radicalisation" among young Palestinians. Cutting sanitation, healthcare and medical services in already poverty-wracked and conflict-ridden areas "would have severe impacts — a cascade of problems that could push the suffering in disastrous and unpredictable directions," he warned. The Trump administration announced in January it was slashing $65 million this year, more than halving its contribution. But the UN said the actual cut was around $300 million because the US had led the agency to believe it would provide $365 million in 2018. The US had been UNWRA's largest donor, supplying nearly 30 per cent of its budget. In announcing the cuts in January, the US State Department said it wanted reforms at the agency, which Israel has strongly criticised. Guterres said reforms are underway, but he sounded a dire alarm about the stakes if UNRWA were to be forced to suspend activities.