British prime minister David Cameron has held talks in Afghanistan with President Hamid Karzai, during a week in which nearly 20 western troops have been killed by the Taliban.
Mr Cameron said there is no question of sending more British troops to Afghanistan.
However, he said Britain will increase the funding and manpower directed towards dealing with roadside bombs.
Britain has about 10,000 troops in Afghanistan, including some 500 special forces.
Mr Cameron said Afghanistan was the British government's "most important foreign policy" and "national security issue".