The EU's top diplomat told reporters in Brussels he would propose that the remaining 10 percent be transferred to the EU budget to be used to boost the capacity of the Ukrainian defence industry.

He said he would submit the proposal to EU member states on Wednesday, ahead of a summit of EU leaders on Thursday and Friday.

Borrell stressed the proposal was to use profits from the assets held in Europe rather than the assets themselves. He said this could yield some 3 billion euros annually.

"The concrete proposal will be tabled tomorrow," he said. "This is for member states to agree."

(Reporting by Andrew Gray, Editing by Charlotte Van Campenhout and Ros Russell)