"Ankara hopes that the negotiations will take place in August," the source said, adding that "nothing is certain yet, and as soon as there is clarity we will inform the public."
Turkish news reported on Saturday that the summit could take place in Russia in late August or early September.
A Russian presidential spokesman said earlier that the presidents had agreed to choose the place and time of their next meeting as soon as possible. The potential talks will focus on Ukraine and the Black Sea grain deal.