"WASHINGTON (Reuters) – U.S. President Barack Obama quietly signed a $7.5 billion aid bill for Pakistan on Thursday that drew criticism in the nuclear-armed South Asian country because of conditions linked to the assistance. Obama signed the bill behind closed doors at the White House without a public ceremony before leaving on a trip to New Orleans. The law provides $7.5 billion in nonmilitary aid to Pakistan over five years. Pakistans military had complained because the legislation ties some funds to fighting militants and is seen by critics as violating sovereignty. The United States is the biggest aid donor to Pakistan and needs its help in hunting al Qaeda leaders and stopping Islamist militants from crossing the border into Afghanistan to fight U.S.-led forces there."