WASHINGTON (AFP) - President Barack Obama Wednesday sanctioned Syrian President Bashar al-Assad and six top aides over their crackdown on popular protests, telling Assad to launch a transition to democracy or step down. Obama signed the executive order to increase pressure on the government of Syria to end its use of violence and begin transitioning to a democratic system that ensures the universal rights of the Syrian people, the document said. The order targets Vice President Faruq al-Shara, Prime Minister Adel Safar, Interior Minister M Ibrahim al-Shaar, Defence Minister Ali Habib Mahmud, Military Intelligence Chief Abdul Fatah Qudsiya, and Mohammed Dib Zaitoun, director of Political Security Directorate. The sanctions block any property the seven have in the US or any in the possession or control of US persons in which the designated individuals have an interest.