"Despite the agreed ceasefire and heavy arms pullout, the threat of the conflict escalation remains," Poroshenko said in a statement published on the president's official webpage.
This comes a day after the leaders of Ukraine, Russia, France and Germany agreed on a 13-point peace plan aimed at stopping the deadly conflict in eastern Ukraine that has claimed lives of more than 5,400 people since April 2014.
The 16-hour talks in Minsk began on Wednesday and stretched into Thursday. The mediators agreed that strict implementation of the new deal would lead to broader political agreements that would ultimately result in Ukrainian reconciliation.
The Ukrainian government is also expected to grant a special status to the self-proclaimed republics of Donetsk and Luhansk, which are to hold local elections under Ukrainian laws, while the Kiev parliament amends the constitution to decentralize power in Ukraine.
