Denmark faced some serious economic problems during the war. The Danish economy was fundamentally hurt by the rising cost of raw material imports such as coal and oil. Furthermore, Denmark lost its main trading partner at that point, the UK. During years of occupation the Danish economy was more and more aligned on meeting German demands, which mainly meant agrarian products. The Danish authorities took an active part in the development and even initiated negotiations on a customs union. Those negotiations failed on the question whether the Danish krone should be abolished.