The United States has accused Syria's President Bashar al-Assad of failing to fulfil a pledge to respect a UN-Arab League peace plan.
State Department spokeswoman Victoria Nuland assailed the Syrian leader, telling reporters that "Assad has not taken the necessary steps to implement" the peace plan crafted by former UN secretary general Kofi Annan.
The plan includes a commitment by the government to halt violence, for troops to be withdrawn from cities and towns, and for humanitarian access.
Earlier Western powers and Syrian opposition groups reacted with scepticism to the Syrian government's acceptance of plan, however Mr Annan said the response was an important initial step.
Syria's opposition factions, who agreed yesterday to name the Syrian National Council as their representative, called on President Assad to pull back his tanks to show he is serious about peace.
The US, China and Germany also called on Syria to match their acceptance of the plan with actions on the ground.
Meanwhile an Arab summit in Baghdad will stop short of calling for Syrian President Bashar al-Assad to quit or discuss arming his foes, both sharply divisive issues, Iraq's foreign minister has said.
The Syria crisis, in which monitors say almost 10,000 people have died in a bloody crackdown on a year-long revolt, has loomed large over the three days of meetings in Iraq, the first such talks hosted by Baghdad in over 20 years.
