Turkish President Recep Tayyip Erdogan said that Turkey will never allow the establishment of a Kurdish state in Syria after major gains by Kurdish fighters.
In a strong-worded warning late on Friday, Erdogan accused the Kurds of ethnically cleansing other communities from land they have taken after pushing back Islamic State forces from the Turkish border.
"I say to the international community that whatever price must be paid, we will never allow the establishment of a new state on our southern frontier in the north of Syria," Erdogan was quoted by Turkish media as telling guests at a dinner to break the Ramadan fast.
He accused Kurdish forces of "changing the demographic structure" of several areas close to the Turkish border, which also have Arab and Turkmen populations.
Kurdish forces have strongly denied those accusations, made repeatedly by Erdogan and other top Turkish politicians.
Turkey has fought a 31-year insurgency in the south east of the country by the Kurdistan Workers' Party (PKK), which is linked to the main Syrian Kurdish People's Protection Units (YPG) militia in Syria.
Erdogan's comments came a day after ISIS terrorists mounted a bloody surprise attack on the Kurdish-held border town of Kobane, killing at least 164.
Kurdish forces have since driven the jihadists out of the highly symbolic Syrian town, which the Kurds wrested back from ISIS in January, according to the Syrian Observatory for Human Rights.
Erdogan again denied persistent claims – and mounting evidence – of Turkish collusion with the jihadists, saying, "It is a big lie to accuse Turkey of having link with a terrorist organization."
Despite ongoing peace talks with the PKK, the creation of any Kurdish zone in the north of Syria deeply worries Turkey, particularly as it borders the already autonomous Kurdistan region of northern Iraq.
The Kurds are the largest stateless people in the Middle East; Kurdistan is currently occupied by Iraq, Syria, Turkey and Iran – although Kurds in northern Iraq have autonomy under the Kurdish Regional Government, and Kurds in Syria have achieved de-facto autonomy via the YPG.
Turkey is one of the fiercest opponents of Bashar al-Assad's regime in Damascus and has taken in more than 1.8 million refugees since the war in Syria began.
But in an interview with the Turkish newspaper Hurriyet, Salih Muslim, the head of the Democratic Union Party (PYD) – the political wing of the YPG militia – denied they were trying to create an independent state. "We do not have such a project," he said.
However, Turkish media speculated Saturday that Erdogan and Prime Minister Ahmet Davutoglu had asked its military to intervene in Syria earlier in the week.
The press claimed that the military high command demanded a written order from the government, with a new one yet to formed after the Justice and Development Party (AKP) lost its overall majority for the first time in 13 years in a parliamentary election on June 7.
Hurriyet also claimed that at least 12,000 Turkish troops were ready to enter Syria to create a "security zone" to protect the border from the threat posed by ISIS.
But many Kurds view reports of possible Turkish intervention in Syria as having more to do with Ankara's opposition to the Kurds than ISIS, noting that until they were driven out by Kurdish fighters ISIS johadists operated openly along Turkey's borders, with no military response from the Turkish military.
AFP contributed to this report.