U.S. and European officials have spoken to the Ukrainian government about what possible peace negotiations with Russia might entail to end the war, NBC quoted an unidentified senior U.S. official and one former U.S. official as saying.

The war in Ukraine, now in its 21st month, has killed or wounded hundreds of thousands and destroyed swathes of the country. It has also triggered the deepest crisis in Moscow’s relations with the West since the 1962 Cuban Missile Crisis.

NBC said the conversations had included very broad outlines of what Ukraine might need to give up to reach a deal with Russia.

Reuters was not able to independently verify the conversations reported by the U.S. television network.

Asked on Saturday about the NBC report, Ukraine’s President Volodymyr Zelenskiy reaffirmed his stance that this was not the time to negotiate with Russia, and he also denied that any Western leaders were pressuring him to do so.

“Everyone knows my attitude, which coincides with the attitude of Ukrainian society … Today no one is putting pressure (on me to negotiate), not one of the leaders of the EU or the United States,” he told a joint news conference with the head of the European Commission, Ursula von der Leyen, in Kyiv.

“For us now to sit down with Russia and talk and give it something – this will not happen.”

Ukraine has repeatedly said it aims to retake all the territory taken by Russia, including Crimea which was annexed in 2014, and that it will not rest until every Russian soldier has been driven from its lands.

NBC quoted the U.S. officials as saying that the conversations with Ukraine came amid concerns in the United States and Europe that the war has reached a stalemate and worries about the West’s ability to continue providing aid to Kyiv.

Russia currently controls about 17.5% of Ukraine’s internationally recognised territory.

Moscow says it had to launch what it calls a “special military operation” in Ukraine in response to what it sees as a hostile and aggressive West it says is using Kyiv to undermine Russia. Kyiv and its Western allies say this is nonsense and that Moscow’s actions are an imperial-style land grab.

The Kremlin says it will achieve all of its aims in Ukraine.