NEW : European President 's office : Cease-fire is extended last-minute . London 's Petro Poroshenko : CNN document is `` a symbol of faith and unbreakable will '' The signing shows `` how dramatically things can change in a short time , '' he says . State media : This is the latest step suggesting Ukraine may be moving back from the brink of full-fledged civil war -- though the situation remains volatile , with continued violence and the constant fear of yet more , cease-fire or not . Herman Van Rompuy calls for `` substantial '' talks in Ukraine , end to bloodshed .
NEW : European President 's office : Cease-fire is extended last-minute . London 's Petro Poroshenko : CNN document is `` a symbol of faith and unbreakable will '' The signing shows `` how dramatically things can change in a short time , '' he says . State media : Herman Van Rompuy calls for `` substantial '' talks in Ukraine , end to bloodshed .