Kiev's delegation in Istanbul is authorized to discuss humanitarian issues and ceasefire terms, the Ukrainian leader has said

Ukraine's Vladimir Zelensky has said he will only discuss territorial issues with Russian President Vladimir Putin.

In an interview with the Hungarian outlet Valasz Online released on Tuesday, Zelensky said the Ukrainian delegation at the talks in Istanbul is not authorized to negotiate territorial issues with the Russian side.

"Our memorandum is a basis for negotiations. Based on it, our delegation has a mandate to discuss humanitarian issues... or the ceasefire," the Ukrainian leader stated.

"What they do not have a mandate for is to discuss the sovereignty and territorial integrity of Ukraine."

This is "our own constitutional matter," he said. "It is my job to have a dialogue about territories - and Putin, who stole them. I will not discuss my position on this with anyone else."

Zelensky's remarks follow the second round of peace talks between Russian and Ukrainian delegations in Istanbul earlier this month.

During the latest talks, both sides exchanged proposals for ending the conflict. Russia's road map for peace requires Ukraine to recognize the loss of five regions that joined Russia in referendums, withdraw its forces from these regions, commit to neutrality, and limit its military capabilities.

The Ukrainian leader has dismissed the proposal, calling it "an ultimatum." Kiev has rejected any territorial concessions, as well as neutrality, and demands a full, unconditional 30-day ceasefire.

In mid-May, Kremlin spokesman Dmitry Peskov said a meeting between Putin and Zelensky cannot be ruled out, and could happen if the talks yield "concrete progress and firm agreements."

Russia, however, has raised concerns over who would sign a potential agreement, as it considers Zelensky "illegitimate." The Ukrainian leader's presidential term ended last year, and he has refused to hold a new election, citing martial law.