The US said that the increasing militancy in the nuclear-armed country is one of the main causes of worry for it. There are militants in Pakistan whose purpose is to overthrow the government of that country, Director of US National Intelligence, Michael McConnell, said. "Osama bin Laden issued a fatwa in the fall of 2007 to say that the mission was to destroy the government of Pakistan," he said in an interview to the popular Charlie Rose Show on PBS. "Pakistan has nuclear weapons. Would you want militants who are sworn to kill Americans in possession of nuclear weapons? That's what I worry about," McConnell said. Referring to the Mumbai terrorist attacks, he said the horrendous terrorist act was carried by a group that was "trained and departed" from Pakistan. "And there's significant tension between those two countries (India and Pakistan) now about how they're going to resolve that. Military forces have been put on an increased state of readiness," he said. McConnell said his worries related to Pakistan was on top because of the increasing militancy in a country, which is nuclear weapon powered. Also, he said his "biggest worry" is the fact that Pakistan as a nation "is teetering on bankruptcy." McConnell said: "It's when you have smart, adaptive, dedicated, willing to die for a cause (of their) leadership whose purpose is mass casualties in the United States. That's the worry. And so now, how would they carry out that act? "It quickly takes one to weapons of mass destruction. How might they obtain them? So that is what we constantly try to monitor and focus on and be aware of." "Would it be biological? Might it be a chemical? Might it be nuclear? Could it morph into something like cyber?" he asked. Stating that there are militants on the Afghan-Pak border who are supported in Pakistan and cross into Afghanistan to attack and kill US and coalition forces, he said: "That's a very unstable situation."