Recep Tayyip Erdoğan has said he will only end Turkey's offensive in northern Syria if Kurdish-led forces withdraw.
It would be the fastest way to end the conflict, he said on Wednesday, adding that he was not willing to negotiate on his position.
The 65-year-old's comments were made a day after he was quoted in Turkish media as saying that he would never declare a ceasefire in the region, and was not worried about reactionary sanctions imposed by the US.
Meanwhile, US Vice President Mike Pence has flown to Ankara to meet with Erdogan and remind him of these sanctions, which the US says will not be lifted until the crisis is resolved.
Turkey has launched its military operation against the Kurdish-controlled areas in order to push forces back from the border area to create a "safe zone", where it wants to eventually return millions of Syrian refugees.
It follows the US decision last week to withdraw its troops from Syria, in a move widely seen as an abandonment of the Kurds, who have been Washington's key ally in the fight against the so-called Islamic State (US).