This week Ukrainian, Russian and separatist negotiators agreed on a roadmap that envisages special status for separatist territories if they conduct free and fair elections under the Ukrainian constitution.
Zelensky's critics fear that Putin will push the comedian-turned-politician to make damaging concessions in order to retain Moscow's de-facto control of separatist regions in eastern Ukraine.
Protesters in Kiev's Independence Square said that agreeing to give broader autonomy to the self-proclaimed Donetsk People's Republic and Lugansk People's Republic would mean surrendering Ukraine's interests.
"We are against a betrayal," protester Sergiy Lezvinsky, 58, told AFP.
"We want to put an end to the occupation, to the decisions that are being fast-tracked".