A Syrian envoy was due to arrive in Turkey on Wednesday for crisis talks with Prime Minister Tayyip Erdogan, days after the Turkish leader described the Syrian government's repression of protests as "savagery".
The once-close relationship between the neighbors appears close to breaking point as thousands of Syrians have fled to Turkey to escape a fierce crackdown by President Bashar Assad's security forces.
State-run Anatolian news agency said Assad's envoy, Hassan Turkmani, was due to arrive in Ankara, where he will face Turkish impatience over Syria's repressive tactics and slowness to reform, as well as anger over a burgeoning humanitarian crisis.
As of Tuesday some 8,500 Syrian refugees were lodged in tented camps on Turkey's side of the border. More have been arriving by the day.
Anatolian reported on Tuesday that Assad had telephoned Erdogan to congratulate him on winning a third term in office in an election on Sunday.
Erdogan, who had a close rapport with Assad, had said before his re-election that once the Turkish poll was over he would be talking to Assad in a "very different manner", and expressed revulsion over repression being used against the Syrian people.
Refugee camps have been established in Turkey's Hatay province, across from the Syrian city of Jisr al-Shughour, just 20 km (13 miles) from the border, where Assad's army launched an offensive on Friday to quell anti-government protests.
Preparations are being made for another influx of refugees far to the east along the 800 km border.
A Turkish Red Crescent official, who requested anonymity, said more tent camps, able to shelter 10,000 people, were being set up near the Turkish city of Mardin and the town of Nusaybin.
Erdogan has called Assad several times since unrest first broke out in Syria three months ago, each time urging reforms and an end to the violence.
In Tuesday's call, Erdogan told Assad to avoid using violence against his people and advised him that reforms should be undertaken as soon as possible, Anatolian reported.
Erdogan also raised concern over protests outside Turkey's embassy in Damascus.
Turkish newspaper Today's Zaman reported that while Turks were voting on Sunday, some 2,000 demonstrators had marched to the Turkish embassy in Damascus and tried to erect a Syrian flag.
Erdogan and Assad have worked to boost cooperation and trade between their two countries, which almost went to war in 1998 due to Syria harbouring Kurdish militants. Nevertheless, Turkey still vies with Iran for influence in Damascus.