U.S. President Barack Obama and British Prime Minister David Cameron showed their unity Wednesday by pledging to stick to the plan of gradually withdrawing troops from Afghanistan, U.S. analysts said.Cameron’s visit came as tensions were flaring up between Afghanistan and NATO forces after Sunday’s shooting spree by a U.S. soldier who killed 16 Afghan civilians and last month’s burning of theQuran at a U.S. military base. The incidents and the ensuing violent protests in Afghanistan have fueled speculations about the possibility of an accelerated U.S. withdrawal.As expected, efforts to end the NATO mission in Afghanistan topped the agenda of the Obama-Cameron summit, during which they also discussed the issues of dealing with Syria’s unrest, Iran’s nuclear crisis and the global economy.The Obama-Cameron summit was just another occasion on which the two close allies showed their solidarity in dealing with global issues, as already demonstrated by London’s staunch support of the U.S.-led invasion of Iraq in 2003.Obama and Cameron said, as the two largest contributors of forces to the Afghan security mission, the two countries would adhere to the original pullout plan from Afghanistan. They also discussed preparations for the NATO summit to be held in Chicago in May, which would determine the next phase of transition in the war-torn country.The United States has announced its strategy to withdraw its combat forces from Afghanistan by 2014 after handing over security responsibilities to the Afghan troops.