BRUSSELS, June 27 (Reuters) - EU leaders have set Monday as the deadline for the release of prisoners in east Ukraine and for the terms of a lasting ceasefire, warning Moscow they were ready to impose further sanctions.

During their summit in Brussels, EU leaders said in a statement on Friday that they also expected Ukrainian authorities should be granted control of three main border checkpoints.

In talks with French President Francois Hollande and German Chancellor Angela Merkel at the summit, Ukrainian President Petro Poroshenko said he had proposed extending the current, temporary ceasefire for 72 hours from Friday's expiry at 1900 GMT. (Reporting by Robin Emmott and Adrian Croft)

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