United Nations peace envoy Kofi Annan has proposed a transitional government for Syria with members from both sides of the country's conflict.
The diplomatic push comes as the death toll in Syria soared.
149 people were reported killed yesterday on the heels of what human rights monitors said was the bloodiest week of the 15-month uprising against President Bashar al-Assad's rule.
Reports from Syria cannot be independently verified as state authorities have barred international journalists and rights groups.
Mr Annan's proposed plan would exclude officials whose presence might jeopardise the transition "or undermine efforts to bring reconciliation."
But Syrian opposition groups have said they would not accept the plan, unless it explicitly required President Assad to step down.
The US, Britain, France, China and Russia have generally backed the plan that will be discussed at a meeting of foreign ministers next Saturday.
However Russia's UN ambassador Vitaly Churkin said there was no guarantee that Mr Annan's document would be agreed to in Geneva.
Turkey, Qatar, Kuwait and Iraq will also be at the meeting, but Iran and Saudi Arabia were not invited.
Both Mr Annan and UN leader Ban Ki-moon had wanted Iran to take part in the talks, as had Russia.
However, the US and European nations have opposed Iran's involvement.
Speaking in Helsinki yesterday, US Secretary of State Hillary Clinton said she had been in regular contact with Mr Annan over his transition plan, without saying what it contained.
President Assad told Iranian state television this evening that a solution imposed on Syria from outside was unacceptable because only Syrians could resolve the country's crisis.
"No non-Syrian model is acceptable because no one but us knows how to solve the problem," Mr Assad said during the rare hour-long interview.
Referring to strained relations with Turkey following the Syria's shooting down of one of its military fighter planes, Assad said there was a difference between the stance of Turkish officials and the positive view of Turkish people towards Syria.
