NATO allies Ankara and Washington agreed on August 7 to establish a safe zone along Turkey's border with northern Syria.
The two have set up a joint operation centre to oversee the so-called zone in the south-eastern Turkish city of Sanliurfa, but it still remains unclear who would control the zone or how wide it would be.
Ankara considers the US-backed Syrian Kurdish militia YPG - which controls large areas of northern Syria at its border - a terrorist group linked to insurgents at home and has long demanded the group be completely removed from the area.
It is also not clear whether the YPG would leave as asked by Turkey.
On Monday, Erdogan said Turkey was ready to send ground troops into northern Syria "very soon" in order to keep its borders safe.
Meanwhile, Turkey is working with Russia "to avoid new massacres and migration waves despite the regime's provocation in Idlib," Erdogan said on Saturday as a ceasefire announced by Russia came into effect in the largely opposition-held Syrian province along the Turkish border.
Turkey backs rebels fighting to oust Syrian President Bashar al-Assad, whose main military backer is Russia.
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