Washington  - The 17,000 extra troops President Barack Obama ordered to Afghanistan will be operational by this summer and in time for the national elections in August, the top commander of US and NATO forces in the country said Wednesday.

But General David McKiernan also told reporters that despite the buildup, the destabilizing and violent situation in Afghanistan is unlikely to be quickly reversed.

"I have to tell you that 2009 is going to be a tough year," McKiernan told reporters at the Pentagon, adding that he expects fighting to increase in the summer.

Washington - The top US commander in Afghanistan said Wednesday that more troops are needed in Afghanistan as quickly as possible, warning the insurgency in the country could worsen.

General David McKiernan said Afghanistan also urgently needs economic and political assistance to defeat al-Qaeda militants and a resurgent Taliban as violence in the country this year has risen to the highest level in years.

"We are in a tough fight," McKiernan told reporters at the Pentagon. "So the idea that it might get worse before it gets better is certainly a possibility in Afghanistan."