"Each day of the war in Donbas costs us around $5 million that we could have invested into sustainable development," he said at the UN Sustainable Development Summit in New York on September 27. In his words, the proponents of war and terrorism have fiercely resisted progress in many parts of the world. "There will be no sustainable development without peace and freedom. Ukraine's bitter experience reveals that peace and freedom are principal pre-conditions for achieving sustainable development goals. Sustainable development is not achievable where explosions are heard and peaceful people are killed," Poroshenko told the summit. According to the president, as a result of Russia's annexation of Crimea and its aggression in Donbas, thousands of people have been killed and critical infrastructure has been ruined; Ukraine has lost about one fifth of its economic potential, he said. Russia's military actions against Ukraine have also increased environmental and epidemiological threats, as well as the risks of social problems, Poroshenko said. He also spoke about the threat of man-made disasters. "In this context, Ukraine believes that it is high time for the United Nations to address the issue of protection of environment in conflicts and it will present specific ideas to this end," he said. In addition, the ongoing crisis which has internally displaced 1.5 million people is the biggest problem not only for Ukraine, but also for the whole region, Poroshenko added. "After putting an end to the military aggression, establishing peace and restoring Ukraine's full sovereignty over the Donbas region and Crimea, it will be extremely important to bring millions of people back to a normal life, restore economic and social infrastructure on sustainable development principles," he said.