The mutual attacks came hours after Russia and Ukraine concluded another round of trilateral peace talks, mediated by the United States. While both sides agreed to prepare another major prisoner swap, other issues, including territory and Europe’s participation in future talks, reportedly caused heated debates at the negotiating table.

A member of the Ukrainian delegation, David Arakhamia, described negotiations as some of the toughest yet, saying the Russians made strict demands and left little room for compromise.

“Every inch of our land will be returned,” Vladimir Medinsky, head of the Russian delegation, said after the negotiations, describing Ukraine as “an abscess that burst.” In addition to demanding Ukrainian territories, the Kremlin called for the establishment of a new security architecture in Europe.

Ukrainian President Volodymyr Zelenskyy said territory remained one of the many topics discussed during the latest round, with the U.S. mediators focusing on different ways to solve the territorial spat, mainly in the Donbas region.

“They believe that to stop this war, we must leave our own territory. It is impossible to speak to us in such a way when it concerns the independence of our country. They are trying to find some variations of this. And I have heard various things,” Zelenskyy said during a press conference in Dublin on Wednesday.

“The idea was something like this: If the war were to stop along the current front line, then parts of the Donetsk and Luhansk regions could subsequently be administratively transferred to the jurisdiction of a different oblast. But that was just one of roughly a million different ideas,” a senior official, who was granted anonymity to discuss classified details, told POLITICO.

“This does not mean that Ukraine will ever recognize the occupied territories as Russian,” the official added.