The Ukrainian president says Monday's talks have been "constructive" as European leaders repeat calls for a ceasefire.

Russia has so far refused to agree to a face-to-face meeting between Zelensky and Putin, despite several requests from Kyiv. The Kremlin hasn't ruled out summits for the two leaders but has said they could only meet in the very final stages of clinching a peace agreement.

The Kremlin is keeping its options open, but analysts said the Russian leader would probably only meet with his Ukrainian counterpart to accept a capitulation.