"We have been discussing the training of the Ukrainian soldiers, also on the soil of Ukraine," Kallas said at a meeting of EU defence ministers.

"We have identified two training centres that could be used for that purpose," she said, without providing details.

The EU has said it could start training Ukrainian forces in their homeland as part of Western security guarantees under any potential agreement to end Russia's four-year war.

The 27-nation bloc has already trained some 90,000 Ukrainian soldiers on EU soil as part of a joint European programme.

An EU official said renovations of the training facilities could start before fighting stops.

Several of Ukraine's European backers -- led by Britain and France -- have said they are willing to deploy their own troops to Ukraine if efforts by the United States end the conflict.

Russia has warned that it would not accept troops from NATO countries on Ukrainian soil and would consider them a "legitimate target".