Russia and China on Thursday vetoed a resolution in the UN Security Council that threatened Syrian authorities with sanctions if they did not withdraw troops from towns and cities and cease using heavy weapons in a crackdown on a 16-month long popular uprising against president Bashar al-Assad.

The vetoed resolution, which would have extended a UN observer mission in Syria for 45 days, received 11 votes in favor, while South Africa and Pakistan abstained.

“The effect of their actions is to protect a brutal regime. They have chosen to put their national interests ahead of the lives of millions of Syrians,” he said.

“This double veto will not stop us,” he added. “We will continue to assist a Syrian opposition on its path to democratic transition in Syria.”

Britain, France, Germany and the United States proposed in the vetoed resolution that international envoy Kofi Annan’s six-point peace plan be placed under Chapter 7 of the U.N. Charter. 

Chapter 7 allows the council to authorize actions ranging from diplomatic and economic sanctions to military intervention.

If the mission is renewed, UN chief Ban Ki-moon has recommended shifting the emphasis of the work of the 300 unarmed military observers to focus on documenting human rights abuses.

UN human rights chief Navi Pillay has gone on record saying there is ample evidence to prosecute Assad for crimes against humanity, should his regime fall.

At present it is believed at least 12,500 people – most of them civilians – have been killed since violence erupted in Syria in March 2012.