A Turkish government official said to AFP on Friday "We are not there yet."
"First and foremost the people of Syria must tell Assad to go. This has not been heard in the streets of Syria," the official said.
"The Syrian opposition is not united and we haven't seen yet a collective call from Syrians to tell Assad to go, like in Egypt and Libya."
On Thursday, US President Barack Obama made the first explicit call for Assad to resign over his regime's attacks on protesters, which was swiftly echoed by the leaders of France, Germany and Britain.
Turkish Prime Minister Recep Tayyip Erdogan and Foreign Minister Ahmet Davutoglu were both in Somalia on Friday to tour areas affected by famine.