Kyiv and its allies aim to rally international support during a peace summit in Saudi Arabia this weekend.
The meeting in Jeddah of national security advisers and other senior officials from about 40 countries is expected to agree on fundamental principles for a future peace settlement to end Russia’s war in Ukraine.
Russia was not invited to attend the meeting, but the Kremlin said it would monitor the discussions.
On Wednesday, Zelenskyy said he hoped the initiative will lead to a “peace summit” of international leaders this autumn to endorse the principles based on his 10-point peace formula.
Zelenskyy’s peace plan calls for the withdrawal of Russian troops and the restoration of its borders.
But Ukrainian, Russian and international officials say there is no prospect of direct peace talks between the warring countries at the moment.