US President Barack Obama has decided to prolong an existing set of sanctions against Syria for one year. Obama cited an “unusual and extraordinary threat” posed by the Arab nation to US national security. The US leader also claimed that the Syrian government's “repression of its citizens” could destabilize the region, as the country has been beset by violent unrest since mid-March 2011. Obama urged Syrian President Bashar al-Assad to step down to make way for a political transition.