The UN chief reiterated his call "for calm and avoiding violence at this sensitive time, while protecting the rights of all Syrians, without distinction", according to Xinhua.
The inviolability of diplomatic and consular premises and personnel must be respected in all cases in accordance with international law, he said.
"We will need the support of the international community to ensure that any political transition is inclusive and comprehensive and that it meets the legitimate aspirations of the people of Syria, in all their diversity. Syria's sovereignty, unity, independence, and territorial integrity must be restored," Guterres added.
"We remain committed to helping Syrians build a country where reconciliation, justice, freedom, and prosperity are shared realities for all. This is the path to sustainable peace in Syria."