"This agreement was reached with President Barack Obama," Poroshenko said.
Answering the question if the conversation with Putin makes sense at all, he said: "There would be no result we are having now without such negotiations."
"The talks are most often carried out in the 'Norman format'. Why so? Because it (the conflict) should not seem to be the problem of Ukraine only. We must engage the world into this process," Poroshenko said.