MOSCOW -- President Vladimir Putin said Russia was open to negotiations over the war in Ukraine and blamed Kyiv and its Western backers for a lack of talks, a stance Washington has previously dismissed as posturing amid persistent Russian attacks.

"We are ready to negotiate with everyone involved about acceptable solutions, but that is up to them - we are not the ones refusing to negotiate, they are," Putin told Rossiya 1 state television in an interview broadcast on Sunday.

An adviser to Ukrainian President Volodymyr Zelenskyy said Putin needed to return to reality and acknowledge it was Russia which did not want talks.

"Russia single-handedly attacked Ukraine and is killing citizens," the adviser, Mykhailo Podolyak, tweeted. "Russia doesn't want negotiations, but tries to avoid responsibility."

Russia's Feb. 24 invasion of Ukraine has triggered the deadliest European conflict since World War Two and the biggest confrontation between Moscow and the West since the 1962 Cuban Missile Crisis.

There is, thus far, little end in sight to the war.

The Kremlin says it will fight until all its aims are achieved while Kyiv says it will not rest until every Russian soldier is ejected from all of its territory.

Putin has said in the past that Russia is open to negotiations but has made clear it must be on his terms, which would involve Ukraine bowing to Moscow's demands and accepting Russia's annexation of four Ukrainian regions. Kyiv, backed by the West, has made clear that is unacceptable.

The U.S. State Department did not immediately respond to a request for comment but , when Russian Foreign Minister Sergei Lavrov voiced an openness to talks, department spokesperson Ned Price told a regular news briefing:

"We see this as posturing. We do not see this as a constructive, legitimate offer to engage in the dialog and diplomacy that is absolutely necessary to see an end to this brutal war of aggression."

'NO OTHER CHOICE'

Russian attacks on power stations have left millions without electricity, and Zelenskyy said Moscow would aim to make the last few days of 2022 dark and difficult.

"Russia has lost everything it could this year. ... I know darkness will not prevent us from leading the occupiers to new defeats. But we have to be ready for any scenario," he said in an evening video address.

The Ukrainian armed forces' general staff said there was still a threat of air and missile strikes on critical infrastructure across the country.

Russian troops had shelled dozens of towns and positions along the front line, it said in a Facebook post.

Zelenskyy, referring to a strike on the southern city of Kherson on Saturday that people, vowed, "We will find every Russian murderer."

Putin accused the West of trying to cleave Russia apart.

"I believe that we are acting in the right direction, we are defending our national interests, the interests of our citizens, our people. And we have no other choice but to protect our citizens," Putin said.

Asked if the geopolitical conflict with the West was approaching a dangerous level, Putin said: "I don't think it's so dangerous."

Kyiv and the West say Putin has no justification for what they cast as an imperial-style war of occupation.

(Additional reporting by Pavel Polityuk in Kyiv and David Ljunggren in Ottawa;Editing by Gareth Jones and Howard Goller)