British Prime Minister David Cameron today ruled out sending more troops to Afghanistan, saying Britain's forces should not stay on "for a day longer" than necessary, according to Reuters. On his first visit as premier to a country his new coalition government has set as its top foreign policy priority, Cameron called 2010 a "vital year" for the Afghan war and said the British public needed to see progress over the next six months. In the month since he took power at the head of a Conservative-Liberal Democrat coalition, Cameron has been conducting an intensive assessment of the situation in Afghanistan, where Britain has 9,500 troops. The risks got personal when Cameron's helicopter was diverted during a tour of military bases in southern Helmand province. An aide described this as a precaution after intercepted comunications suggested insurgents might try to shoot it down. Rising casualties -- nearly 300 British soldiers have been killed since 2001 -- are eroding British public support for the war. Its spiralling cost worries a Cameron government searching for deep spending cuts to rein in a gaping budget deficit. "No one wants British troops to stay in Afghanistan for a day longer than is necessary," Cameron told a joint news conference with Afghan President Hamid Karzai at the presidential palace. "What we want, and in our national security interest, is to hand power over to an Afghanistan that is able to take control of its own security," he said. The number of foreign troops in Afghanistan is about to peak at around 150,000 but the death of 18 international soldiers this week alone shows that the Taliban are at their strongest since they were overthrown in the 2001 U.S.-led invasion.