The United States weathered criticism of its human rights record from friends and foes alike on Friday in a United Nations forum in Geneva that the administration of President George W. Bush had boycotted as hypocritical. Senior American officials defended the United States against allegations that it used torture and said the Obama administration had begun “turning the page” on practices of the Bush administration that had caused global outrage. But the United States’ conduct in its wars in Iraq and Afghanistan and its campaign against terrorism  notably its treatment of prisoners at Guantánamo Bay in Cuba and the Abu Ghraib jail near Baghdad  have come under heavy criticism from human rights organizations. The Obama administration is committed to closing Guantánamo and ensuring that all detainees, no matter where they are held, are treated humanely, American officials said. “Between Iraq, Afghanistan and Guantánamo, we have conducted hundreds of investigations regarding detainee abuse allegations, and those have led to hundreds of disciplinary actions,” a State Department legal adviser, Harold Hongju Koh, told the forum.