Peace could be achieved in Ukraine in a matter of weeks, Polish Prime Minister Donald Tusk said on Tuesday after talks with other European leaders, Canada and NATO.

He made his remarks despite the Kremlin saying its negotiating position would toughen after accusing Kyiv of attacking a Russian presidential residence, an allegation that Kyiv said was baseless and intended to prolong the conflict.

“Peace is on the horizon, there is no doubt that things have happened that give grounds for hope that this war can end, and quite quickly, but it is still a hope, far from 100% certain,” Tusk told a government meeting.

“When I say peace is on the horizon, I’m talking about the coming weeks, not the coming months or years. By January, we’ll all have to come together… to make decisions about the future of Ukraine, the future of this part of the world.”

Tusk said security guarantees offered to Kyiv by the United States were a reason to hope the conflict could end soon, but that Kyiv would need to compromise on territorial issues.

US President Donald Trump said after talks with Ukrainian President Volodymyr Zelensky on Sunday that they were “getting a lot closer, maybe very close” to an agreement to end the war, although “thorny issues” remained.

Zelensky said control of Ukraine’s Zaporizhzhia nuclear station, which is in Russian hands, and the fate of the Donbas area of eastern Ukraine were still unresolved.

Russia wants Kyiv to withdraw troops from parts of the Donetsk region it has failed to occupy in almost four years of war since its invasion of Ukraine in February 2022.

Kyiv wants fighting halted along the current front lines, and Washington has proposed a free economic zone if Ukraine pulls troops back.