Russia said on Wednesday that a neutral status for Ukraine with its own limited army, similar to Austria’s, was being considered as a compromise in peace talks with Kyiv, while Ukraine spoke of outside powers guaranteeing its security.

Russia invaded Ukraine on February 24, in what it calls a special military operation to demilitarise and “denazify” Ukraine, but has made only stuttering progress and failed to seize any of its major cities.

Bolstered by the strength of its defence, Ukraine says it is ready to negotiate to end the war, but not to surrender or accept Russian ultimatums.

Vladimir Medinsky, Russia’s chief negotiator, told state television: “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.”

RIA news agency quoted Kremlin spokesman Dmitry Peskov as saying this option “could really be seen a compromise”.

In his latest rallying cry to Ukraine’s citizens, President Volodymyr Zelenskiy said any peace deal must protect their country from future threats.

“We can and must fight today, now. We can and must defend our state, our life, our Ukrainian life,” he said in a video address. “We can and must negotiate a just but fair peace for Ukraine - real security guarantees that will work.”

The atmosphere around the talks has become more positive after three weeks of war that have killed thousands of people and displaced several million Ukrainians.

Even if the security question can be resolved, enormous issues remain, including the status of the Crimean peninsula, which Russia seized from Ukraine in 2014, and that of two largely Russian-speaking regions of eastern Ukraine - the Donbas - which Moscow has recognised as independent states.

Crimea and Donbas

Medinsky said Crimea and the Donbass remained key questions, along with humanitarian issues including “denazification” - an allusion to Russia’s allegation that Ukraine, which has a democratically elected government and president, is run by extreme nationalists.

Russian Foreign Minister Sergei Lavrov told Russian RBC news that there was also focus on the rights of Ukraine’s native Russian-speakers, some of whom complain that they are forced to speak Ukrainian or seen as second-class citizens.

But he said that, on “neutral status” and security guarantees, “there are absolutely specific formulations which in my view are close to agreement”.

Kyiv’s chief negotiator, Mykhailo Podolyak, said a model of legally binding security guarantees that would offer Ukraine protection by 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” he said on his Telegram channel.

“This means that the signatories of the guarantees do not stand aside in the event of an attack on Ukraine, as today,” he said, “but they take an active part on the side of Ukraine in the conflict and officially provide us with an immediate supply of the necessary amount of weapons.”

He said Ukraine also wanted to be sure that its skies could quickly be closed to air attacks - the kind of “no-fly” zone that Kyiv has in vain urged the Western NATO alliance to impose.

President Vladimir Putin has said Moscow cannot let Ukraine join NATO because that would pose an existential threat to Russian security.

Austria, which Russia is 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.