Diplomatic moves toward ending the conflict -- in which more than 100,000 people have died, according to U.N. estimates -- continued this week.
U.N. envoy to Syria Lakhdar Brahimi talked with Syrian President Bashar al-Assad in Damascus on Wednesday in their first meeting since December.
Brahimi spoke to al-Assad about the framework for holding a planned conference involving all parties in the conflict in Geneva, Switzerland.
Al-Assad told Brahimi that any political solution to the crisis in Syria hinges on outside countries cutting off support to the rebels, according to state-run media.
"Any success for any political solution must be linked to the end of any military support to military groups and to pressure the countries that are supporting these groups and are facilitating the entry of the terrorists and mercenaries into Syria by providing money and military support," al-Assad said during the meeting, according to Syrian state television.
He added, "This is an important step to prepare the framework to allow a national dialogue and put clear mechanisms to reach the desired objectives at the upcoming peace talks."
The Syrian conflict began in March 2011 after government forces cracked down on peaceful protesters during the Arab Spring movement and is now a full-blown civil war.