German Chancellor Angela Merkel said Europe’s discord over refugees threatens the euro warning European Union leaders that the situation will be very difficult.

“If we disintegrate into small countries again, a common currency will be very difficult,” Merkel said at a party rally on Monday in Volkmarsen, Germany.

“What we are seeing in recent days, with certain countries going their own way to the detriment of another country like Greece — that isn’t the European way.” she said, as Bloomberg reports.

With countries along the Western Balkans route closing their borders and blocking refugees from heading north from Greece, Mrs. Merkel warned other EU nations on Sunday against allowing “chaos” to develop in a country that already “has many problems.”