A senior US. defense official says elements of al-Qaida still remain in Pakistan and unless more is done to stop the flow of recruits into militant groups the war on terror will never be won. Visiting US Undersecretary for Defense Douglas Feith told a news conference in Pakistan that disrupting and destroying terrorist networks is not enough. He said the war on terror can not be won without stopping the flow of people into the ranks of terrorist groups. He also said terrorists must be denied what they need to survive and operate. Pakistan is a key US ally and has handed over more than 500 militants to the United States. But hundreds of al-Qaida militants are still hiding in the Pakistan-Afghan border region.