White House officials indicated that the current confusion could delay a decision over a possible troop surge in the region. Barack Obama's administration has been holding off on a decision to send more troops to Afghanistan until a credible government is installed in Kabul. If there is a run-off between Mr Karzai and his main rival, former foreign minister Abdullah Abdullah, UK troops will help transport ballot boxes and voting papers to and from remote polling stations, but will maintain a low profile around the poll - to be held by mid-November to beat the winter. Afghan police and soldiers will provide security.