“In Berlin Poroshenko will show Kyiv's willingness to comply with the Minsk agreements and continue the dialogue with Western partners,” the source told Interfax-Ukraine on Friday. “On the one hand, it is clear that the negotiations are aimed to show that we are "friends against Moscow." On the other hand, it is Poroshenko's opportunity to convince the West that Putin is bluffing and there is no reason to be horrified by a possible nuclear war. And therefore, it is possible to raise the more important issue of replacing the "Minsk" and "Normandy" formats with some others. Ukraine will never agree to limit its legal sovereignty over the occupied territories and the decentralization amendments to the Constitution are the maximum concession on the part of the President,” the source said.