The US military's most senior officer has warned there will be an increase in bloodshed in Afghanistan this year. Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, told reporters in Washington that it may be difficult to accept, but we must prepare ourselves for more violence and more casualties in coming months. The violence will be worse in 2011 than last year in many parts of Afghanistan, he added. Admiral Mullen said, Taliban leaders have been eliminated in the troubled provinces of Kandahar and Helmand. But the gains made by the Afghan and international troops were tenuous and fragile, he said. 2010 has been the deadliest year so far for foreign troops in Afghanistan since the Taliban were ousted in 2001. Last year saw a massive surge in violence in Afghanistan with more than 700 NATO troops killed. The US President Barack Obama has said US forces would begin pulling out of Afghanistan in July 2011.