The US on 28 June formally handed over sovereignty to the interim Iraqi government, two days ahead of schedule. The surprise move appears to have been designed to prevent any large scale attacks by insurgents to coincide with the transfer. In a low key ceremony in Baghdad's Green Zone, home of the Coalition Provisional Authority (CPA), CPA leader Paul Bremer ceded leadership in the country to interim Prime Minister Iyad Allawi, before leaving the country. 'I leave Iraq confident in the future and confident in the ability of the government to meet the challenges of the future,' said Bremer. Washington's top representative in Iraq will from now on be the new US ambassador John Negroponte.