One of President Assad's last remaining friends in the region has called on him to step down.

Turkish Prime Minister Tayyip Erdogan has reluctantly concluded that his friend and ally must go. Reuters:

Turkish Prime Minister Tayyip Erdogan called on Tuesday for Syrian President Bashar al-Assad to step down for the sake of peace in the region and said Turkey could not turn its back on the Syrian people.

Erdogan said Assad should learn a lesson from the fate of Muammar Gaddafi -- the Libyan leader toppled by rebels in August and killed after his capture last month -- and that criticism of the Syrian government's violent crackdown on protesters did not amount to a call for international military intervention.

In a further signal Turkey was stepping up pressure on its one-time ally, Turkish broadcaster CNN Turk reported that Turkey's land forces commander had travelled to a city near the Syrian border to inspect Turkish frontier troops.

"Without spilling any more blood, without causing any more injustice, for the sake of peace for the people, the country and the region, finally step down," Erdogan said in a speech aimed directly at Assad.

"We do not have eyes on any country's land, we have no desire to interfere in any country's internal affairs.

"But when a people is persecuted, especially a people that are our relatives, our brothers, and with whom we share a 910 km border, we absolutely cannot pretend nothing is happening and turn our backs," Erdogan said.

Turkey will not send troops in to protect Syrians, but they may facilitate the revolt by allowing the Free Syrian Army - a loosely organized group of army defectors - to continue to use Turkish soil to train and build its forces.

It took Erdogan long enough to make this decision. For months, he has offered little criticism of Assad. But last month, as it became clear that Assad wasn't going to voluntarily leave office, Turkey began applying sanctions and upped the rhetoric against the Syrian president. Erdogan has now taken the plunge and joined the rest of the region - except Iran, Lebanon, and Yemen - in calling for Assad's retirement.