Updated

Turkey will not tolerate the creation of a Kurdish-run region in Syria, its prime minister said Thursday following reports that Kurdish rebels and a Syrian Kurdish political party had taken control of five cities along the Syrian-Turkish border.

Recep Tayyip Erdogan's comments underscored Turkey's concern that the creation of a Kurdish authority in the north of Syria could provide a sanctuary to Turkey's own Kurdish separatists, who took up arms against the state in 1984. The Kurdish rebels already use northern Iraq as a springboard for attacks in Turkey.

The prime minister said Turkey's military is closely monitoring the developments. He warned the Kurdistan Workers Party, or PKK, which is fighting for self-rule in Turkey's southeast, and the Democratic Union Party of Syria, known as the PYD, to avoid any attempt at collaboration.

Otherwise, "it would not be possible for us to tolerate and watch this," Erdogan told reporters before departing to London for the opening of the 2012 Olympic Games. "No one should attempt to provoke us. If a step needs to be taken against the (PKK) we would not hesitate to take it."

The conflict between Turkey's Kurdish rebels and the government has killed tens of thousands of people over the past 28 years. Kurds also make up substantial portions of the population in the neighboring countries of Syria, Iran and Iraq.

Erdogan said Foreign Minister Ahmet Davutoglu would meet officials from Iraq's Kurdish regional government next week to relay Turkey's concerns over the PKK taking up positions along the border with violence-torn Syria and to urge Iraqi Kurds not to support a Kurdish-run region in Syria.

Erdogan said Davutoglu would tell Kurdish officials in northern Iraq, "We have trust in you, but please do not be a party to any wrong moves."

As Syrian President Bashar Assad has cracked down on an increasingly armed opposition movement over the past 16 months -- a conflict that has left thousands dead and morphed into a civil war -- Turkey has emerged as one of Assad's fiercest critics and taken in some 44,000 refugees from the Arab state.

On Thursday, Erdogan said he believed Assad was "on his way out" and that Syria was preparing "for a new era." He said a transitional government should prepare for a new constitution as well as presidential and parliamentary elections.

The Turkish leader again would not rule out the possibility of setting up a buffer zone to protect Syrians along the border if the security situation deteriorates. The buffer zone on Syrian soil would aim to guarantee the security of Turkey's border and the welfare of Syrian civilians fleeting the violence.

"A safe zone, a buffer zone, refugee camps -- all of these are possible alternatives," Erdogan said. "Their priorities will depend on the situation; they will be assessed according to the process that unfolds."