KIEV: Ukrainian President Poroshenko on Wednesday called for European peacekeepers to enforce a shattered ceasefire deal in east Ukraine after a flashpoint strategic town fell to a fierce assault by pro-Russian rebels.

Some 2,500 exhausted government troops retreated from Debaltseve -- a key railway hub linking the main separatist-held cities of Donetsk and Lugansk -- after rebels ignored a supposed truce to seize control of the town.