Top U.S. officials are calling for greater efforts to prevent civilian deaths in Afghanistan.

U.S. Defense Secretary Robert Gates said Friday every civilian casualty "is a defeat" for U.S.-led forces and "a setback for the Afghan government."

Gates also accused Iran of playing a "double game" in Afghanistan saying it wants good ties with Afghan people while giving insurgents weapons and support.

Gates spoke in Brussels after NATO members threw their support behind a plan aimed at shifting momentum in the fight against the Taliban.

The new plan calls for an overhaul of the military command structure in Afghanistan, centralizing control of military and training operations as the United States prepares to send an additional 21,000 troops to battle the Taliban.

The new commander of U.S. and allied forces in Afghanistan, General Stanley McChrystal, told NATO defense ministers he takes his responsibility "very, very seriously."

NATO Secretary-General Jaap de Hoop Scheffer warns the alliance's efforts in Afghanistan will not be easy at a time when "enemies" are killing civilians and burning schools.

Afghanistan has seen a surge in violence in recent months.  NATO says attacks between January and May were up nearly 60 percent compared to the same time last year.  And the commander of U.S. forces in South Asia and the Middle East, General David Petraeus, says the violence will likely increase as international forces attack militant sanctuaries and safe havens.  

But more help could soon be on the way.  Spain has pledged to send another 450 troops to help with security during the upcoming election, although the move still needs approval from parliament.

Afghan officials said Friday a roadside bomb blast killed three Afghan soldiers in the eastern province of Paktika.  Britain's Ministry of Defense said a blast killed a British soldier a day earlier near the southern city of Kandahar.

Some information for this report was provided by AFP, AP and Reuters.