"This is a variant that is currently being discussed and which could really be seen a compromise," Kremlin spokesman Dmitry Peskov was quoted as saying by RIA news agency.

He was speaking nearly three weeks after Russia invaded Ukraine on February 24, in what it calls a special military operation.

Peskov was commenting on remarks from Vladimir Medinsky, Russia's chief negotiator, who earlier told state TV: "Ukraine is offering an Austrian or Swedish version of a neutral demilitarised state, but at the same time a state with its own army and navy."

Ukraine has not confirmed it is willing to discuss neutrality. It says it is ready to negotiate to end the war, but not to surrender or accept Russian ultimatums.

A Ukrainian negotiator said a model of legally binding security guarantees that would offer Ukraine protection from a group of allies in the event of a future attack was "on the negotiating table".

"What does this mean? A rigid agreement with a number of guarantor states undertaking clear legal obligations to actively prevent attacks," negotiator Mykhailo Podolyak said on Twitter.

Officials on both sides have made cautiously positive statements in recent days on progress towards a possible agreement after three weeks of war that have killed thousands of people and displaced several million Ukrainians.

"Neutral status is now being seriously discussed along, of course, with security guarantees," Russian Foreign Minister Sergei Lavrov told RBC news earlier on Wednesday.

"Now this very thing is being discussed in negotiations - there are absolutely specific formulations which in my view are close to agreement," Lavrov said.

Austria, which Russia is now citing as a potential model, is bound to neutrality by its constitution, which prohibits entry into military alliances and the establishment of foreign military bases on its territory.

Australian Associated Press