Ukrainian President Volodymyr Zelensky will meet his Turkish counterpart Recep Tayyip Erdogan and UN Secretary-General Antonio Guterres this week, a spokesman for the world body confirmed.
The meeting is scheduled to take place on Thursday in the Ukrainian city of Lviv, Xinhua news agency quoted UN spokesman Stephane Dujarric as saying.
The agenda of the meeting has not been revealed.
On Friday, Guterres is due to visit a seaport in Odesa.
The meeting comes after Ukraine and Russia in late July concluded agreements with Turkey and the UN to guarantee a transport route for ships carrying agricultural goods from the war zone.
Since then, 36 passages have been approved, 21 ships left Ukraine for the Bosporus and 15 moved through the strait in the direction of the war-torn country.
It is estimated that more than 20 million tonnes of grain products are stuck in Ukraine since Russia launched its war on February 24 and blockaded the country's ports.
More than a quarter of all outgoing grain shiploads have so far been destined for Turkey, 22 per cent for Iran and South Korea, 8 per cent for China and 6 per cent for Ireland, the UN said.