More: President Obama thanked Russian President Putin for role in Iran nuclear talks, White House says; both leaders 'expressed a desire to work together on reducing regional tensions, particularly in Syria'
The uprising in Syria was sparked in March 2011 in the southern city of Daraa with demonstrators angered by the arrests of young people who scrawled anti-government graffiti. Their grievances and calls for reforms were met with a violent security crackdown, reportedly by by President Bashar al-Assad's forces. The unrest served to catalyze anti-government protests across the nation.
More than 20,000 people have been killed since the uprising broke out, according to the Britain-based Syrian Observatory for Human Rights in August 2012. In August 2012, Arab states -- including Saudi Arabia and the UAE -- urged their citizens to leave Lebanon after a mass kidnapping in retaliation for events in Syria raised fears that violence could be spilling across the region. - AFP, CNN, AP, Reuters
Toward the end of 2012, parties including Russia and UN peace envoy Lakhdar Brahimi have worked to broker a peace deal between the Syrian regime and rebel forces.