Gul said the violence in Turkey's southern neighbor, where a revolt against President Bashar al-Assad has evolved into a civil war that threatens to draw in regional powers, could not go on indefinitely and Assad's fall was inevitable.
"The worst-case scenarios are taking place right now in Syria ... Our government is in constant consultation with the Turkish military. Whatever is needed is being done immediately as you see, and it will continue to be done," Gul said.
"There will be a change, a transition sooner or later ... It is a must for the international community to take effective action before Syria turns into a bigger wreck and further blood is shed, that is our main wish," he told reporters in Ankara.
Turkey's armed forces have bolstered their presence along the 900-km (560-mile) border with Syria in recent days and have been responding in kind to gunfire and shelling spilling across from the south, where Assad's forces have been battling rebels who control swathes of territory.