Secretary of State Hillary Rodham Clinton greeted the rival Protestant and Catholic leaders of Northern Ireland's power-sharing government Monday on a mission to urge them to keep their awkward coalition working, AP reported. Clinton met First Minister Peter Robinson and Deputy First Minister Martin McGuinness on the front steps of Stormont Castle _ itself a diplomatic accomplishment, because the rival leaders hadn't appeared together in months. Robinson, leader of the British Protestant majority, has resisted years of pressure from McGuinness and the Irish Catholic minority for their administration to take responsibility for Northern Ireland's police and justice system. Britain retained those key powers when Northern Ireland politicians agreed to share power in 2007, but had expected to transfer them to local hands by now. The governments of Ireland and the United States agree with Britain that transferring law-and-order powers to Belfast would strengthen power-sharing, the central accomplishment of the U.S.-brokered Good Friday peace accord of 1998. They argue it also would undermine Catholic support for Irish Republican Army dissidents who continue to attack British security forces in Northern Ireland. But reflecting the enmity eroding their coalition, Robinson and McGuinness were meeting separately with Clinton inside Stormont Castle. Clinton was scheduled later Monday to deliver a speech to the 108-member Northern Ireland Assembly, with the Irish Catholic bloc on her left, the British Protestants to her right.