LONDON (REUTERS) - British Prime Minister David Cameron on Wednesday called on the Ukrainian authorities to pull back security forces surrounding protesters in Kiev, telling Ukrainian President Viktor Yanukovich the world was closely watching his actions.

"I am deeply concerned by the scenes we are witnessing in Ukraine," Cameron said in a statement released by his office."The violence on all sides is completely unacceptable and President Yanukovich has a particular responsibility to pull back government forces and de-escalate the situation.

"President Yanukovich should be under no doubt that the world is watching his actions and that those responsible for violence will be held accountable."