Obama wins key backing for Syria strike

US President Barack Obama won the backing of two top Republicans in Congress in his call for limited US strikes on Syria to punish president Bashar al-Assad for his suspected use of chemical weapons against civilians.

Speaking after the United Nations said two million Syrians had fled a conflict that posed the greatest threat to world peace since the Vietnam war, Obama said the United States also has a broader plan to help rebels defeat Assad’s forces.

In remarks that appeared to question the legality of plans to strike Syria without UN backing, UN secretary-general Ban Ki-moon said the use of force was only legal in self-defence or with UN Security Council authorisation.