The European Union will debate the launch of a major training operation for Ukrainian forces in nearby nations, the bloc's foreign policy chief Josep Borrell said Monday.

The proposal will be discussed next week at a two-day meeting of EU defence ministers which gets underway in Prague on Monday, Borrell told a press conference in Santander, in northern Spain.

"I hope it will be approved," he added.

"Of course it would be a big mission, I think it would be a big mission," he said, adding "any mission has to be up to the level of the conflict".

Russia invaded Ukraine on February 24, sparking the worst conflict in Europe in decades which has killed tens of thousands of civilians.

Military hardware and intelligence data from Europe and the US have allowed Ukrainian forces to slow -- but not stall -- Russian forces in the Donbas and along the Black Sea coast.

"It seems reasonable that a war that is lasting and looks set to last requires an effort not only in terms of supplies of material," Borrell said.

"This is what is being discussed among the member states and will be discussed politically next week," he added.

Borrell, a former Spanish foreign minister, said the details of the military training operation would have to be agreed by all EU member states.

He said "several" nations already provide military training to Ukrainian forces under bilateral agreements.

Britain for example has since July offered instruction to Ukrainian soldiers at sites across the country.

The programme aims to train up to 10,000 Ukrainian soldiers in Britain in weapons handling, battlefield first aid and patrol tactics.

Borrell recalled that the EU regularly deploys "training missions with the armies with which we are cooperating".

"We have been doing it in Mali until recently we have now started in Mozambique and we have done it in Niger, Chad, in many countries," he said.

Borrell was in Santander to take part on a conference on "the birth of geopolitical Europe" organised by a local university.