Speaking Wednesday at the Pentagon U.S. military headquarters, Gen. David McKiernan said more military presence is "needed as quickly as possible," CNN reported.
The general said the threat to U.S. troops, which he said has risen significantly from last year, comes from "an increased number of fighters" reaching Afghanistan from neighboring Pakistan's lawless tribal regions, CNN reported.
He said additional support should include "boots on the ground," helicopters, increased intelligence assets, logistics and transportation.
Last week, CNN said, U.S. Defense Secretary Robert Gates announced a Marine battalion will go to Afghanistan in November, followed by an Army brigade in January. However, no more forces will be available for Afghanistan duty until spring or summer of next year, the U.S. network said.
As for Pakistan's current operations against militants in the tribal areas, McKiernan said he is "cautiously optimistic."
"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.