The aide, Yuri Ushakov, told reporters that Russia was willing in principle to take part in such a summit that would gather the leaders of Russia, Ukraine, France and Germany, an idea pushed by French President Emmanuel Macron.
But Ushakov said no date had yet been fixed and that Moscow had three preconditions before it would agree to attend.
Rival armed forces in eastern Ukraine should be separated on either side of the line of contact, he said, wording on the special status for the Donbass region should be agreed, and there should also be a preliminary agreement on what the summit's conclusions should be.
Kiev's forces have been battling pro-Russian separatists in the Donbass region of eastern Ukraine since 2014 in a conflict that has claimed more than 13,000 lives. Sporadic fighting continues despite a ceasefire agreement.
Ushakov said he did not rule out the summit taking place in October.