WASHINGTON ( CNN ) -- The commander for NATO forces in Afghanistan said Wednesday that more military presence is `` needed as quickly as possible . '' U.S. troops are seeing an increased threat in Afghanistan , Gen. David McKiernan says . Gen. David McKiernan said the additional military capability is needed because of `` an increased number of fighters '' coming into Afghanistan from Pakistan 's lawless tribal regions . `` It 's a significant increase from what we saw this time last year , '' he said at the Pentagon . `` We 're facing a tougher threat right now , especially in the east where we have the U.S. division , '' he said . `` And so the additional military capability [ is ] needed as quickly as possible . '' He said what 's necessary includes `` boots on the ground '' as well as support such as `` helicopters , increased intelligence assets , logistics , transportation and so on . '' Just over a week ago , Defense Secretary Robert Gates said that a Marine battalion will head to Afghanistan in November and an Army brigade in January , but no more forces will be available for deployment to Afghanistan until spring or summer of 2009 . The week before Gates ' announcement , McKiernan had asked for four more brigades -- three more than the one approved to go in January . Three brigades add up to as many as 12,000 troops . The defense secretary , speaking before the Senate Armed Services Committee last month , expressed caution about adding too many troops in Afghanistan . `` I think we need to think about how heavy a military footprint the U.S. ought to have in Afghanistan , '' he told the committee . Instead , Gates said , there should be a focus on increasing the size of the Afghan army . McKiernan , who took command of NATO 's International Security Assistance Force earlier this year , said his request of an additional 3,500 people to train the Afghan army and police is still under review . McKiernan noted that he is `` cautiously optimistic '' regarding Pakistan 's military operations against Taliban and al Qaeda fighters inside its borders . `` What we 're seeing is Pakistani leadership taking on a deteriorated militant sanctuary in the tribal areas that has deteriorated over last several years , '' he said . McKiernan said it is `` probably too early '' to see if Pakistan 's military clampdown in its tribal areas has had any effect on stemming militant activity in Afghanistan . `` We 're watching those very closely to see if there 's a cause and effect with the strength of the insurgency on the Afghan side of the border , '' he said . `` But we think that 's a positive step that they are taking on those militant sanctuaries . ''
More foreign fighters entering Afghanistan from Pakistan , general reports . ` ` We 're facing a tougher threat , '' so more is needed ` ` as quickly as possible '' . Gen. David Gale commands American forces in Afghanistan . McKiernan has sought out more brigades of U.S. troops than one promised .