Poroshenko said it during a phone conversation with German Chancellor Angela Merkel.
Russian President Vladimir Putin earlier talked with Merkel and French President Francois Hollande over phone, calling for resuming a ceasefire regime as soon as possible and the meeting of the three-party Contact Group.
"We are seeing that Ukraine is not curbing violence. On the contrary, the punitive operation is getting tougher and it is spiralling and spreading," said the spokesman, adding a stable ceasefire should be guaranteed.
"Russia wants to settle down the Ukraine crisis as soon as possible. The implementation of the Berlin agreements, especially the ceasefire regime, should be the top priority."
According to Ukrainian National Security and Defence Council, 23 of the total 36 districts seized by militants in the eastern regions of Donetsk and Luhansk have been retaken by the Ukrainian army.