Afghanistan is facing a fresh crisis over its presidential election with one of the leading candidates reportedly boycotting an audit of the vote. The move by Abdullah Abdullah has disrupted a U.N. audit aimed at resolving claims of fraud from both sides. It also comes amid tensions between the United States and Afghan President Hamid Karzai. Karzai’s spokesperson told Reuters Tuesday Karzai will not attend a key NATO summit next week because he disagrees with the United States over the future of troops in Afghanistan.