US Secretary of State Hillary Clinton has called on European and other countries to impose more economic sanctions to try to force Syrian president Bashar al-Assad to stand down.
Speaking in Paris on Friday, Mrs Clinton condemned Mr Assad's "brutality against unarmed citizens", adding that the violence must stop and he needed to step aside.
She called for "strong new sanctions targeting Syria's energy sector to deny the regime the revenues that fund its campaign of violence".
The BBC reports the issue of oil sanctions is to be discussed at a meeting in Poland on Friday of European Union Foreign Ministers.
The US has already banned the import of Syrian oil.
Meanwhile, activists in Syria are preparing for another day of protests, under the slogan "death rather than humiliation".
They said that another seven people were killed by security forces on Thursday.