The NATO mission in Afghanistan says insurgent attacks have killed four of its soldiers as British Prime Minister David Cameron visited the capital, Kabul, and pledged to increase British aid to the country.

NATO said Tuesday a roadside bombing in eastern Afghanistan killed three NATO troops while another attack in the east killed a fourth soldier. The nationalities of the four troops were not disclosed.

British Prime Minister Cameron met Afghan President Hamid Karzai in Kabul and promised to build an enduring relationship with Afghanistan even as it begins to withdraw British troops from the country in the coming months. Britain plans to provide $287 million in aid to Afghanistan in the 12 months ending in April 2012, up from $164 million in the previous 12-month period.

Britain has 9,500 troops in Afghanistan, mostly in the south, representing the second largest foreign troop contingent after the United States. Mr. Cameron said Britain will withdraw some of those forces this year and next year before ceasing all combat operations in the country by the end of 2014. He is due to provide details of the pullout to the British parliament on Wednesday.

Mr. Cameron arrived in Afghanistan Monday, visiting British troops in the southern province of Helmand. His visit was overshadowed by the death of a British soldier who disappeared in Helmand earlier in the day. The soldier's body was found with gunshot wounds after an extensive British search. The Taliban claimed responsibility for his death.

Speaking at a joint news conference with Mr. Karzai on Tuesday, Mr. Cameron called on the Taliban to stop bombing, killing and fighting and to join the political process to be a part of Afghanistan's future. He said Afghanistan can learn from Britain's experience in Northern Ireland, where he said Irish separatist militants behind deadly attacks on civilians and security forces later became politicians involved in governance.

Mr. Cameron also said Britain will build a military academy in Afghanistan modeled on England's Sandhurst Academy to train Afghan army officers. He said the academy will be staffed by British personnel and is due to open in 2013.