US and Iraqi negotiators have abandoned efforts to conclude a comprehensive agreement governing the long-term status of UStroops in Iraq before the end of the Bush presidency, according to senior US officials, effectively leaving talks over an extended US military presence there to the next administration. In place of the formal status-of-forces agreement negotiators had hoped to complete by July 31, the two governments are now working on a "bridge" document, more limited in both time and scope, that would allow basic US military operations to continue beyond the expiration of a UN mandate at the end of the year.