The top US commander in Afghanistan on Wednesday welcomed the White House's decision to send more combat troops, but cautioned that fighting will be difficult in the months ahead. "Even with these additional forces, I have to tell you that 2009 is going to be tough year," Gen. David McKiernan told a news conference. US President Barack Obama on Tuesday approved the dispatching of 17,000 more US troops to Afghanistan to stabilize what he called a deteriorating situation. They include an Army combat brigade and a Marine expeditionary brigade and will join the approximately 30,000 US troops already there. McKiernan said the extra troops would be sufficient for what he believes needs to be done through mid-year, when the fighting tends to be heaviest. He described the Obama decision as meeting about two-thirds of his overall needs in combat capability over the coming three to five years.