The U.S. military is sharply increasing humanitarian aid to Pakistan after the worst earthquake in the country's history, Defense Secretary Donald Rumsfeld and other senior officials said on Tuesday, according to Reuters. President George W. Bush has offered an initial $50 million in U.S. emergency aid to Pakistan, which has been a close ally in Washington's war on terrorism. Bush's government, criticized for an initially slow response to last December's Asian tsunami and for a sluggish reaction to Hurricane Katrina on the U.S. Gulf Coast in August, has already sent helicopters and planeloads of disaster aid to Pakistan. Tens of thousands of people were killed in the weekend quake. Additional C-17 and C-130 cargo planes, two U.S. military engineer battalions and four big CH-47 and CH-53 helicopters were going to Pakistan, said a senior Bush-administration official, who spoke on condition of anonymity. As many as 36 additional U.S. helicopters were put on standby to go to Pakistan, the official added. The Pentagon said eight helicopters already were in Pakistan. The United States was also using reconnaissance aircraft, including unmanned drones, to survey damage from the quake, Pentagon spokesman Lawrence Di Rita said in Washington. --More 2310 Local Time 2010 GMT