"Today's designation of al-Khayr by the US and the UN will help to ensure that that Al-Qaida remains in severe financial straits," Under Secretary for Terrorism and Financial Intelligence Stuart Levey said.
Al-Khayr appears on a 2009 list of 85 persons wanted by the government of Saudi Arabia, in part because of his role as an Al-Qaida financial facilitator.
He has transferred hundreds of thousands of dollars for a specific terrorist attack against US interests, the Treasury Department said in a statement.
Al-Khayr also acts for Al-Qaida in a leadership role on the media committee, and has on at least one occasion recruited a member for it.
His relationship with Al-Qaida began with military training the terrorist group provided him in the mid-1990s.
He has also provided services to Osama bin Laden as a bodyguard. "After the death in May of Mustafa Abu al-Yazid, who essentially served as Al-Qaida's chief financial officer, we will continue to work with our allies to target those like al-Khayr who could step into al-Yazid's shoes," said Levey.