Recep Tayyip Erdogan said Turkey has stopped a Syrian-flagged ship in the Sea of Marmara in the past, the state-run Anatolia news agency reported. He did not say when the ship was stopped or whether any weapons were found aboard it.
"If there are planes carrying weapons, or such shipments by land, then we would stop and confiscate them as in the past," the Anatolia quoted Erdogan as saying.
Turkey intercepted an arms shipment from Iran to Syria in August. In March, Turkish authorities also seized the cargo of an Iranian plane bound for Syria because the shipment violated U.N. sanctions. Turkish media said the aircraft was carrying light weapons, including automatic rifles, rocket launchers and mortars.
Erdogan said this week that Turkey was coordinating its efforts with the U.S. Washington has called on Syrian President Bashar Assad to resign and imposed sanctions on some Syrian officials, blocked assets they may have in the U.S. and banned any U.S. import of Syrian oil or petroleum products.
Erdogan told Turkish journalists after talks with President Barack Obama in New York late Tuesday that he was no longer in contact with Syria's leadership.
"I have cut all contacts with the Syrian administration," Erdogan said. "We never wanted things to arrive at this point, but unfortunately, the Syrian administration has forced us to take such a decision."
Turkey is Syria's neighbor and an important trade partner and Erdogan had cultivated a close friendship with Assad. But Turkish leaders have grown increasingly frustrated with Damascus over its refusal to halt the crackdown on opposition protesters and to carry out reforms.
Earlier this month, Turkey hosted a group of Syrian opposition figures who declared a 140-member Syrian National Council in an effort to present a united front against President Bashir Assad. About 7,500 Syrians are seeking refuge from the violence in six camps in Turkey, near the border.