"The escalation of the conflict and the impact of the crisis on Lebanon are extremely dangerous," Mr Ban said at the opening of the World Forum for Democracy in Strasbourg in France.
The armed uprising in Syria has increasingly sparked violence on the country's border with NATO member Turkey. Yesterday the military returned fire after a shell launched from Syria struck the border village of Akcakale. There were no casualties in that incident but last Thursday five civilians were killed in the village by shelling from Syria.
Since last Thursday the Turkish military has responded in kind whenever Syrian ordnance has breached its territory, inflaming tensions between the former allies and leading to fears of a broader conflict.