BRUSSELS (AFP) - Nato expressed concern Monday about whether enough security could be provided to ensure the safe conduct of elections in Afghanistan if polls are brought forward to April. "Our concern is not the internal politics of the country. This is a sovereign country and they have not just the authority but also the structures in place to handle it," NATO spokesman James Appathurai said. "Our business is security and we are in the process of enhancing our capability for elections that, until now, the Afghan independent electoral commission had designated to be for August," he said. "We will be able to have more capability in Afghanistan to support an August election than we would if an earlier date would be chosen." In a decree Saturday, President Hamid Karzai said an election would be held according to the constitutional timeline, which says the vote must be 30 to 60 days before his five-year term expires on May 21. The Independent Electoral Committee has insisted more time is needed to ensure free and fair elections can be held in adequate security, saying such concerns were more important than following the letter of the constitution. NATO's top military officer US General John Craddock is seeking four extra battalions of troops to help provide security. Depending on the country it is drawn from, a battalion usually numbers between 800 and 1,200 troops. NATO officials have privately expressed concern that forces might have to be diverted from other operations to meet security needs in Afghanistan should the elections be advanced. "Neither the United Nations nor NATO are capable of providing security for or organise elections before April 20," a NATO diplomat said, on condition of anonymity. "August 20 is the date that seems most realistic and reasonable," he said. The elections are seen as a litmus test of NATO's efforts to help spread democracy across strife-torn Afghanistan, in the face of a Taliban insurgency, and foster reconstruction. The United States recently announced the deployment of 17,000 extra troops, mainly to the south where the insurgency is at its worst, but those soldiers are unlikely to be fully in place until July, under current planning. "The worst thing for Afghanistan would be to have an election that descends into violence and where the people don't have the chance to express their views," a senior US official said Monday. "The constitution and the legalities are things that can be dealt with in legal mechanisms," he told reporters in Brussels. "Afghanistan has institutions that could chart a path forward and that's far less violent and far less disruptive for the future of the country than an election that descends into violence."