The agreement also includes a temporary cease-fire during evacuations.
Ukrainian presidential adviser Mykhailo Podolyak said that the sides had discussed humanitarian corridors and agreed to speak again.
"To our great regret, we did not get the results we were counting on," Podolyak said.
Previously, Ukrainian President Volodymyr Zelenskyy asked his Russian counterpart Vladimir Putin to "stop this war," underlining the need for the two leaders to speak without preconditions.
Moscow and Kyiv began a second round of talks in western Belarus earlier on the same day, just hours after Putin reiterated his country's demands in a telephone conversation with his French counterpart Emmanuel Macron.