The arrival of 12,000 extra U.S. combat troops in southern Afghanistan this summer is not likely to bring major security gains to the volatile region until 2010, Reuters cited a top NATO commander as saying today. Dutch Major General Mart de Kruif, who commands NATO's 22,300-strong International Security Assistance Force in southern Afghanistan, expects "a significant spike" in violence as fresh U.S. and NATO forces enter the region ahead of Afghan elections due in August. "I think that what we are doing now is actually planting the seeds and that we'll view a significant increase in the security situation across southern Afghanistan next year," Kruif told Pentagon reporters in a video conference. Southern Afghanistan, a six-province area where NATO forces operate under a command called Regional Command-South, is the country's most violent region.