The Saudi monarch has arrived in Damascus for a highly significant visit that is the strongest indication yet of thawing relations between the two rival nations following years of tension.
King Abdullah's visit on Wednesday is the first by a Saudi ruler since the 2005 assassination of former Lebanese Prime Minister Rafik Hariri, a close Saudi ally.
Syria was widely blamed for his death, but denies any responsibility.
The two Arab countries have also been at odds over several regional issues, including Syria's close ties with the Shi'ite Iran. They have recently made moves toward a rapprochement with three meetings between Abdullah and Syrian President Bashar Assad in the past two years.
Many hope a full reconciliation will help ease regional tensions.