US President George W. Bush on Tuesday warned countries not to harbour or support terrorists or else they would be overthrown from power like the Taliban in Afghanistan. "We have made clear that governments that sponsor terror are as guilty as the terrorists - and will be held to account," Bush said in his speech on 'Defense Transformation' at the US Military Academy in New York. "After 9/11, we applied the doctrine to Afghanistan. We removed the Taliban from power. We shut down training camps where Al Qaeda planned the attacks on our country," Bush said. Referring to the Mumbai attack, Bush said: "The terrorists continue to pose serious challenges, as the world saw in the terrible attack in Mumbai last month." Al Qaeda's top two leaders remain at large. Yet they are facing pressure so intense that the only way they can stay alive is to stay underground. The day will come when they receive the justice they deserve, he said. Bush said: "We must stand by the friends and allies who are making tough decisions and taking risks to defeat the terrorists. We must keep up the pressure on regimes that sponsor terror and pursue weapons of mass destruction."