ISTANBUL, TURKEY - MARCH 13 : People release red balloons to mark the third anniversary of Syria conflict at Sultanahmet square in Istanbul, Turkey on March 13, 2014. Red balloons are simultaneously relased in squares around the world to mark the conflict's anniversary that began on March 15, 2011. Elif Ozturk / Anadolu Agency

ISTANBUL, TURKEY - MARCH 13 : People release red balloons to mark the third anniversary of Syria conflict at Sultanahmet square in Istanbul, Turkey on March 13, 2014. Red balloons are simultaneously relased in squares around the world to mark the conflict's anniversary that began on March 15, 2011. Elif Ozturk / Anadolu Agency

ISTANBUL, TURKEY - MARCH 13 : People release red balloons to mark the third anniversary of Syria conflict at Sultanahmet square in Istanbul, Turkey on March 13, 2014. Red balloons are simultaneously relased in squares around the world to mark the conflict's anniversary that began on March 15, 2011. Elif Ozturk / Anadolu Agency

WASHINGTON, DC - MARCH 13 : Activists of the 'With Syria' campaign hold an image of a girl holding a red, heart-shaped balloon, by British street artist Bansky during a 'vigil of solidarity' to mark the third anniversary of the start of the Syrian conflict at the Capitol Reflecting Pool in Washington, DC, on March 13, 2014. Activicts take part in the worldwide campaign to mark the third anniversary of the devastating civil war and call for an end of the conflict in Syria. Basri Sahin / Anadolu Agency

WASHINGTON, DC - MARCH 13 : Activists of the 'With Syria' campaign hold a 'vigil of solidarity' to mark the third anniversary of the start of the Syrian conflict at the Capitol Reflecting Pool in Washington, DC, on March 13, 2014. Activicts take part in the worldwide campaign to mark the third anniversary of the devastating civil war and call for an end of the conflict in Syria. Basri Sahin / Anadolu Agency

WASHINGTON, DC - MARCH 13 : Activists of the 'With Syria' campaign hold a 'vigil of solidarity' to mark the third anniversary of the start of the Syrian conflict at the Capitol Reflecting Pool in Washington, DC, on March 13, 2014. Activicts take part in the worldwide campaign to mark the third anniversary of the devastating civil war and call for an end of the conflict in Syria. Basri Sahin / Anadolu Agency

WASHINGTON, DC - MARCH 13 : Activists of the 'With Syria' campaign hold a 'vigil of solidarity' to mark the third anniversary of the start of the Syrian conflict at the Capitol Reflecting Pool in Washington, DC, on March 13, 2014. Activicts take part in the worldwide campaign to mark the third anniversary of the devastating civil war and call for an end of the conflict in Syria. Basri Sahin / Anadolu Agency

WASHINGTON, DC - MARCH 13 : An ctivist holds a red balloon during the 'With Syria' campaign to mark the third anniversary of the start of the Syrian conflict at Roosevelt Island's FDR Four Freedoms Park in New York City, on March 13, 2014. Activicts around the world take part in the 'With Syria' campaign to mark the third anniversary of the devastating civil war and call for an end of the conflict in Syria. Bilgin Sasmaz / Anadolu Agency

WASHINGTON, DC - MARCH 13 : Activists hold red balloons and signs during the 'With Syria' campaign to mark the third anniversary of the start of the Syrian conflict at Roosevelt Island's FDR Four Freedoms Park in New York City, on March 13, 2014. Activicts around the world take part in the 'With Syria' campaign to mark the third anniversary of the devastating civil war and call for an end of the conflict in Syria. Bilgin Sasmaz / Anadolu Agency

WASHINGTON, DC - MARCH 13 : Activists hold red balloons and signs during the 'With Syria' campaign to mark the third anniversary of the start of the Syrian conflict at Roosevelt Island's FDR Four Freedoms Park in New York City, on March 13, 2014. Activicts around the world take part in the 'With Syria' campaign to mark the third anniversary of the devastating civil war and call for an end of the conflict in Syria. Bilgin Sasmaz / Anadolu Agency

WASHINGTON, DC - MARCH 13 : Activists of the 'With Syria' campaign hold a candlelight vigil to mark the third anniversary of the start of the Syrian conflict at Roosevelt Island's FDR Four Freedoms Park in New York City, on March 13, 2014. Activicts around the world take part in the 'With Syria' campaign to mark the third anniversary of the devastating civil war and call for an end of the conflict in Syria. Bilgin Sasmaz / Anadolu Agency

WASHINGTON, DC - MARCH 13 : Activists hold red balloons and signs during the 'With Syria' campaign to mark the third anniversary of the start of the Syrian conflict at Roosevelt Island's FDR Four Freedoms Park in New York City, on March 13, 2014. Activicts around the world take part in the 'With Syria' campaign to mark the third anniversary of the devastating civil war and call for an end of the conflict in Syria. Bilgin Sasmaz / Anadolu Agency