Syria said Thursday it would begin requiring visas from Turks entering the country, reversing a six-year agreement with Ankara that allowed visa-free entry to citizens of both countries.
The foreign ministry said the new measure was in response to a decision taken by Turkey on December 9, but it did not elaborate.
"The Syrian government, in virtue of the principles of reciprocity and national sovereignty, decided to refuse entry to Syria for Turkish citizens without visas," a ministry statement said.
"The Turkish government is responsible for the consequences (of this decision) on the ties between the Syrian and Turkish peoples," added the statement, published by state news agency SANA.
But a spokesman for the Turkish foreign ministry told AFP there was "not a single change in the visa policies for Syrians", who are allowed to remain in Turkey visa-free for stays up to 90 days within a six-month period.
Once an ally of Damascus, Ankara cut diplomatic ties with President Bashar al-Assad after the beginning of Syria's uprising in March 2011.
Turkey has become a leading backer of the opposition to Assad, and Syria accuses it of supporting "terrorist groups."