Turkey has seized a Syrian-flagged ship loaded with weapons, Turkish Prime Minister Recep Tayyip Erdogan has said.

He did not say where or when the vessel was stopped, but vowed to confiscate any arms shipments for Syria coming through Turkish waters or airspace.

"Turkey has arrested a ship flying the Syrian flag and carrying weapons," Mr Erdogan said in New York where he attended the UN General Assembly. "If in the future arms shipments (to Syria) are made by air or land, we will stop and seize them," he added, BBC reported.

Earlier this week, Mr Erdogan told reporters that Turkey no longer had any contacts with the Syrian leadership and warned of sanctions. Ankara also hosted a conference of Syria's opposition groups earlier this month.