Russia said on Thursday that Ukraine would "of course" be involved in talks to end the war, but there would be a separate US-Russian strand to the negotiations.
Kremlin spokesman Dmitry Peskov also said it could take up to several months to arrange a meeting between presidents Vladimir Putin and Donald Trump.
The two leaders spoke on Wednesday and announced their intention to meet face-to-face, shortly after Trump's defense secretary bluntly told allies that Washington did not support NATO membership for Ukraine and that it was an illusion to believe that Ukraine - a fifth of which is controlled by Russia - could return to its pre-war borders.
Peskov told Russian state TV in an interview: "One way or another, of course, Ukraine will participate in the negotiations."
He added: "There will be a bilateral Russian-American track of this dialogue, and a track that will be related to Ukraine's involvement."
His comments were unlikely to reassure Kyiv or allay the concerns of European governments that are demanding a place at the table, fearful that Moscow and Washington could otherwise cut a deal that undermines their security.
"Any agreement without us will fail, because you need Europe and Ukraine to also implement the agreement," European Union foreign policy chief Kaja Kallas said.
"Any quick fix is a dirty deal."
Trump and Putin spoke for over an hour on Wednesday, the first known direct contact between US and Russian presidents since Putin had a call with Joe Biden shortly before sending his army into Ukraine in February 2022.
Peskov told reporters earlier that the Kremlin was impressed by Trump's position on ending the war.
He said there was political will on both the Russian and US sides to find a settlement.
"There is a political will which was emphasized during yesterday's conversation to conduct a dialogue in search of a settlement," Peskov said. "There is agreement that a peaceful negotiated settlement is possible."
Asked about European demands to be represented in Ukraine peace talks, Peskov said: "As for Europe's participation, there is no understanding yet of the format of a possible negotiation process, so it is premature to talk about it."