The United States has asked Pakistan to take decisive steps against the terrorists operating from its soil. US Secretary of State Hillary Clinton who arrived in Islamabad on Friday on an unannounced visit, said she had asked Pakistan's President, Prime Minister as well as the Army chief to do more to fight militants.She described her visit to Pakistan as a turning point saying that though Osama bin Laden was dead but al-Qaeda and its syndicate of terror remain a serious threat.