Russia and Ukraine discussed further prisoner swaps on Wednesday at a brief session of peace talks in Istanbul, but the sides remained far apart on ceasefire terms and a possible meeting of their leaders.

Negotiators for the warring sides in Istanbul appeared to make little progress on ceasefire terms or a possible summit between their presidents – with their meeting ending after less than an hour.

While both sides acknowledged progress on humanitarian issues, talks on a full ceasefire remain stalled. Turkish Foreign Minister Hakan Fidan called for "result-oriented negotiations" to end the devastating war.