The visit, his first to the Gulf since his country descended into conflict in 2011, coincides with heightened diplomatic efforts to end the four-year conflict in Syria.
Oman sees itself as a conciliator in a volatile region and has a history of constructive relations with Syria’s close ally Iran.
In the meeting, Mouallem and Omani Foreign Minister Yusuf Bin Alawi agreed it was time to bring together “constructive efforts” to end the crisis, the Syrian state news agency SANA said.
It reported that the men said any solution “should be based on meeting the aspirations of the Syrian people in the fight against terrorism” and should ensure the stability, sovereignty and territorial integrity of Syria, SANA said.
Mouallem was accompanied by Syrian Deputy Foreign Minister Faisal Mekdad, SANA said.
Mouallem visited Tehran earlier in the week for talks on the war amid increased efforts by Iran and Russia, both allies of Syrian President Bashar Al-Assad, to end the conflict and build a wide international alliance against the Islamic State of Iraq and Syria (ISIS).
Syrian state TV quoted Mouallem as saying on the visit that Syria supported any efforts to combat ISIS if they were coordinated with Damascus, but anything else would “be a breach of Syrian sovereignty”.
Iran and Russia have stood by Assad, providing military and financial support during the conflict. The United States and some of its Gulf Arab allies have said Assad must leave office.
During Mouallem’s visit to Tehran on Wednesday, Iranian President Hassan Rouhani reiterated “Iran’s unwavering support for the Syrian nation in the face of terror groups”, Iranian state media reported.